[Transcriber's note: Extensive research found no evidence
that the U.S. copyright on this publication was renewed.]

Penny Nichols
Finds a Clue

By

JOAN CLARK

The Goldsmith Publishing Company
CHICAGO

COPYRIGHT MCMXXXVI BY
THE GOLDSMITH PUBLISHING COMPANY
MANUFACTURED IN THE UNITED STATES OF AMERICA

CONTENTS

Penny Nichols Finds a Clue

CHAPTER I

A Warning

Penny Nichols flung open the office door of the Nichols Detective Agency, descending upon a dignified, gray-haired man who was busy at his desk.

"Dad," she announced, "I've come to report a mysterious disappearance!"

Christopher Nichols dropped the correspondence upon which he was working and regarded his daughter for a moment, his gray eyes flashing an indulgent welcome.

"What sort of disappearance?" he inquired cautiously.

Penny laughed as she opened her purse, disclosing an empty coin container.

"It seems to be my allowance again. Yesterday I had two dollars. Now the old pocketbook is as bare as Mother Hubbard's cupboard!"

Mr. Nichols' chief interest in life centered about his charming young daughter and he found it hard at times to keep from pampering her. It was especially difficult at this very moment as Penny stood there, her blue eyes twinkling mischievously, her full red lips parted in an enticing smile, and a few unruly ringlets of curly golden hair framing her forehead in an artistry both casual and becoming.

"Now that is a most bewildering case," he agreed with mock seriousness. "I don't suppose that rattle-trap roadster of yours might offer a clue to the mystery?"

"I'm afraid it does," Penny admitted. "Only this time I indulged in seat covers instead of spare parts. As a result I'm flat broke. And I'm to meet Susan Altman at the tennis courts in ten minutes."

Mr. Nichols smiled indulgently as he reached into his pocket for a roll of bills.

"I'll come to the rescue this time, young lady, but mind, I'm charging it up to next week's allowance."

"That's fair enough." Carelessly, Penny picked up several papers from the desk, studying them curiously. "What's this? A new case?"

Her father nodded as he quickly retrieved the documents.

"I've been hired by the Reliance Insurance Company to track down a gang of auto thieves."

"Sounds interesting."

"Unless I miss my guess it will prove a baffling case. I am afraid we may have to postpone our vacation trip to the mountains, Penny."

"Can't you arrange to capture the bold, bad men a little ahead of schedule?" Penny bantered.

"I wish it would prove as simple as that."

"It seems a shame to give up the vacation, because you've worked so hard lately. You really need a long rest."

"We'll both take it when this case is solved," Mr. Nichols promised. "Run along now, for I'm particularly busy."

Not in the least offended by the abrupt dismissal, Penny blew her father an impudent kiss as she went out the door.

Since the death of Mrs. Nichols many years before, Penelope and her father had lived together in a large white house on Hilburn Street with only Mrs. Gallup, an elderly housekeeper, to see that the establishment ran smoothly. It was not surprising that under such an arrangement the fifteen-year-old girl enjoyed rare freedom. Yet Penny never abused her privileges and she enjoyed the complete confidence of her father.

Penny owned her own roadster and drove it well. To be sure, the car was a second-hand model, but one of which she was very proud, for she had paid for it herself by teaching swimming at the Y.W.C.A. Automobiles, Penny discovered to her chagrin, had an unpleasant way of breaking down at odd moments, and for that reason her expense account usually was far ahead of her allowance. Occasionally, Mr. Nichols came to her rescue with very acceptable gifts of tires and spare parts.

Reaching the tennis court, Penny parked her car on a near-by street. She found Susan Altman, her chum, already awaiting her.

"It's almost too hot today for tennis," the dark-haired girl complained as she took her position at the baseline of the cement court, preparing to serve the first ball.

For two long hours the girls battled back and forth. Although usually they were well matched, upon this particular day Susan found herself unable to cope with her companion's sizzling service and well-placed drives. Finally, after completely missing a ball which Penny had sent over the net with bullet-like speed, she threw down her racquet in disgust.

"I've had enough punishment! That makes the third straight set you've won."

"It's getting almost too dark to see the ball," Penny said generously. "Shall we call it an evening and finish off with something to eat?"

They crossed over to Eby's Café, a favorite haunt of Belton City's younger set. The booths were quite deserted.

"Everyone seems to have gone away for the summer," Susan mourned as she pondered over the menu. "I suppose you'll be leaving soon too, Penny."

"No chance of it, I'm afraid. Dad has become involved in a new case which may keep us in town indefinitely."

"I wish my father were a detective," Susan commented a trifle enviously. "It's too bad about the vacation of course, but your life is exciting at least."

It seemed to her that Penny always led an unhampered, adventurous existence. At any rate, the girl was well acquainted with interesting happenings at the Belton City police court and had more than a nodding acquaintance with fascinating personages of the city.

"I've never had any real adventures," Penny declared gloomily. "Unfortunately, Dad is a little secretive about his sleuthing activities. I'd give anything to know about this latest case——"

Her voice trailed off for the two girls had heard a shrill warning whistle which they instantly recognized as the fire siren. Although they had not even begun their suppers they rushed to the plateglass window to watch the red engine clatter by.

"Why, it's turning down our street!" Susan exclaimed. "Oh, I hope our house isn't afire!"

"Let's jump in my car and follow," Penny proposed.

They hurriedly left the café. Penny had parked her roadster just out of sight around the corner. But as they viewed the car, they both stopped short in amazement.

"The rear wheel is gone!" Susan gasped. "Surely that can't be your roadster, Penny!"

It had grown quite dark outside and for an instant both girls believed they had made a mistake in identifying the car. Yet one glance at the license number assured them that they had made no error. A daring thief had jacked up the rear axle, stealing an almost new wheel which Penny's father had purchased for her only the previous week. An inspection disclosed that the spare wheel also had been taken.

"I never heard of such an outrage!" Penny stormed. "Why, we couldn't have been in that café fifteen minutes! The theft was accomplished almost under our eyes!"

"I hope the loss is covered by insurance," Susan said anxiously.

"I don't know whether it is or not. Dad looks after everything like that. Oh, dear, unless I can get in touch with him, we're practically stranded here."

Although the girls were only a short distance from Mr. Nichols' office they were nearly a mile from their homes. The roadster had been parked several blocks from a street car line.

"We won't be able to learn about the fire either," Susan worried. "I wonder if it could have been at our house?"

"It isn't likely, but let's telephone and make certain."

Even as she spoke they heard the fire engine returning from its recent run.

"It couldn't have been much of a fire," Susan commented in relief. "At least it's out now."

"I'll see if I can get in touch with Dad," Penny offered.

She was relieved to find Mr. Nichols still at his office. After listening to an excited account of all that had befallen, he promised to come over immediately and take charge of the stripped roadster.

Ten minutes later he drove up in his sedan.

"This isn't as unfortunate as it appears," he told the downcast Penny. "The loss is completely covered by insurance. Besides, I have a dark suspicion that this little job was handled by the same gang of men I am after. I may glean a few valuable clues."

After making a brief inspection of the car Mr. Nichols turned his own sedan over to Penny, directing her to take it home while he attended to the stripped roadster and reported to the police.

Susan had promised to spend the night at the Nichols home, so the girls drove directly toward the house on Hilburn Street. Despite Mr. Nichols' matter-of-fact attitude regarding the theft, they considered it an event of major importance. They were so absorbed in an animated discussion of the affair that they were taken completely by surprise when a policeman held up his hand for Penny to stop.

"Now what have I done?" she murmured in alarm, bringing the sedan to a sudden halt at the curbing. "I hope I haven't crashed a light."

The officer stepped up to the car window.

"Aren't you Miss Nichols?" he questioned.

"Why, yes, I am." Penny was slightly relieved at his tone.

"I recognized your car and knew you lived in the neighborhood. I thought I'd give you a friendly warning."

"A warning? I don't understand."

"We're on the lookout for a crook who vanished somewhere in this vicinity," the officer explained. "In fact, he ran through the hedge which borders your place."

"Did you search the grounds?" Penny asked with interest.

"Yes, but he made his get-away. I just thought I'd tip you off to be careful."

"We'll be on the lookout," Penny promised. "Thanks for telling us."

The officer moved aside and she drove on again.

"I've had almost enough excitement for one evening without encountering a desperado," Susan declared with a little shiver as they approached the Nichols residence. "I wonder why they're after the man?"

"He's probably a jail breaker," Penny returned carelessly.

Susan studied her chum admiringly.

"You're the most casual person I ever knew, Penelope Nichols. Didn't that warning give you the creeps?"

"To tell you the truth I didn't think much about it. The man would be miles from here by this time."

Nevertheless, as she turned the car into the gravel driveway, Penny's keen gaze swept the dark grounds.

Susan likewise surveyed the yard anxiously. Suddenly she uttered a low cry, nervously clutching her companion's arm.

"I saw a shadow just then!" she whispered tensely. "I do believe someone is hiding in the lilac bushes!"

CHAPTER II

Inside the Trunk

Penny instantly halted the car on the driveway, peering in the direction which her chum indicated.

"I don't see anyone," she insisted. "Perhaps the shadow you saw was caused by that big tree."

She pointed to a large oak which shaded the rear porch of the Nichols' home. Its swaying boughs did produce grotesque silhouettes upon the path near the lilac bushes.

"You may be right," Susan admitted reluctantly. "Only I was almost positive I saw someone."

"I think your nerves are a tiny bit on edge to-night," Penny laughed. Even so she was not quite sure Susan was mistaken.

She drove the sedan into the dark garage. As she was preparing to close the heavy double doors she thought she heard a step on the gravel path.

"Is that you, Mrs. Gallup?" she called.

There was no answer.

"I was right," Susan whispered tensely. "Someone is prowling about the grounds."

"There's no one about," Penny maintained after peering carefully around. "Probably I imagined that I heard footsteps. Come on, let's go to the house."

It was reassuring to see a light burning in the kitchen. The window shades had not been drawn and from the outside, Mrs. Gallup could be observed washing dishes. As the girls came in she greeted them in obvious relief.

"I'm so glad you're back, Penny. I was beginning to be afraid that something had happened to you."

"Quite a bit did happen," Penny laughed. "By the way, you haven't seen anyone prowling about the yard this evening, have you?"

"Why, no, I've been so busy that I've scarcely glanced out the window. Early this afternoon a tramp stopped at the door for food. After I gave him a sandwich he went off. I hope he hasn't come back to make trouble."

"Oh, no," Penny assured her quickly, "I'm sure there's no need for alarm."

"Then why did you ask?"

Penny was forced to relate what the policeman had told her, although she realized that the warning would worry the housekeeper.

"Dear me, I don't feel safe with your father gone. To think that so much has been going on around here and I didn't know a thing about it! Why, I haven't even locked the doors!"

"I doubt that it will be necessary now," Penny said, peering into the refrigerator to see what she could find for a belated supper. "Dad will soon be home anyway."

"I'm going to lock all the doors and windows this minute," Mrs. Gallup insisted firmly. "With so much silverware in the house, it isn't wise to take any chance."

Lowering the window blinds in the dining room, the housekeeper went directly to the buffet, removing a quantity of choice silverware which had been in the Nichols family for several generations. Leaving the girls to forage their own supper, she carried the box upstairs, intending to lock it in her own bureau drawer. Returning again to the lower floor she scurried about closing doors and slamming down windows.

"Since she's bent upon doing such a thorough job, I suppose I should help," Penny remarked to her chum. "Finish your supper while I lock the back door."

"Don't forget to set out the milk bottle before you barricade us in," Susan laughed.

Penny picked the bottle up from the kitchen table and crossed the porch to place it on the step. It took her so long outside that Susan came to the door to learn what detained her. She was astonished to behold Penny standing as rigid as a statue, her eyes riveted upon the garage door.

"What's wrong?" Susan inquired.

"Didn't I close that door when I put the car away?" Penny demanded in a low tone.

"Why, yes, I'm sure you did. The wind must have blown it open."

Penny shook her head.

"The door has a special catch so I know it couldn't have opened by itself. Susan, I believe someone has sneaked into the garage since we left it!"

Susan's eyes dilated with fear. Involuntarily, she took a step backwards, turning toward the kitchen door.

Penny caught her by the hand.

"Don't tell Mrs. Gallup or she'll go into hysterics. Let's find out if there really is anyone in the garage before we call the police."

At first Susan hung back, but when she found that Penny was determined to investigate the garage alone, she reluctantly followed her chum down the path.

Cautiously, they peeped into the garage. It appeared to be deserted.

"I'll get Dad's flashlight from the sedan pocket," Penny whispered.

She tiptoed across the cement floor. Groping about inside the car she found the light, but before she could turn it on she was startled to hear a slight sound overhead.

Penny's heart began to beat a trifle faster. She was almost certain that someone was hiding in the little room above the garage. In former years it had been occupied by a chauffeur whom Mr. Nichols employed, but now that the detective drove his own car it was used only for the storage of a few old boxes and trunks.

"Don't you dare go up there!" Susan whispered tensely, sensing the thought in her chum's mind. "It isn't safe."

"It's safe enough if you stand guard here at the door," Penny insisted. "If anything goes wrong scream for Mrs. Gallup."

Before Susan could stop her she tiptoed across the cement floor and quietly crept up the stairway leading to the storage room.

Reaching the top step Penny paused to listen. She could hear no unusual sound, yet a certain intuition warned her that someone was in the room.

Systematically, she flashed the beam of her light over the walls. Nothing appeared amiss.

"My imagination is running riot tonight," she thought in disgust. "There's no one here."

She started toward the stairway, but paused, unable to rid herself of the conviction that all was not as it should be. Then her light chanced to focus for an instant upon an old trunk in one corner of the room. Beside it in a crumpled heap lay an old rug.

From her father Penny had learned to be an unusually keen observer. She was positive that upon her last visit to the storeroom, the carpet had covered the trunk, protecting it from dust.

Summoning her courage, she cautiously approached the trunk. She paused to listen again. Distinctly, she could hear the sound of soft breathing.

Suddenly she flung back the lid. A man cowered inside.

"Don't make a move," Penny warned coolly, blinding him with the light. Protected as she was by the darkness, he could not know that she had no weapon.

"Don't shoot!" he pleaded, stepping from the trunk with hands held above his head.

It was then that Penny observed that her prisoner was a mere boy. He did not appear to be more than a year or two older than herself.

"March down the stairs in front of me and don't try any tricks," she ordered, trying to keep her voice steady.

She had grown a little frightened at her own daring. It appeared reasonable to suppose that the youth she had captured was the same crook whom the police had warned her against and yet the boy seemed too young to be a hardened criminal.

Penny decided upon a bold move.

"Susan, stand guard at the outside door," she directed.

As her chum took the position, Penny reached up and switched on the garage light.

"I have no weapon," she admitted, knowing that the youth had perceived the fact instantly. "But it will do you no good to try to escape for the police are combing the neighborhood."

Her words had the desired effect. Blinking in the unexpected glare of the light, the young fugitive shrank back against the wall, his face twisted by fear.

"Do they suspect I'm here?" he questioned. "Have they surrounded the district?"

"I talked with an officer only a few minutes ago," Penny answered truthfully. "He advised me that our property was being watched."

She was studying the boy with increasing interest. He was exceedingly well dressed and while his garments were in need of pressing they fitted him perfectly, disclosing a fine physique. He had broad shoulders and powerful muscles. It struck Penny that he looked more like a football player than a crook. Yet, as she studied his face, she realized that it lacked character.

"Don't turn me over to the police," the boy begged. "I've done nothing wrong."

"Then why were you hiding in my garage?"

"It's true the police were chasing me," he admitted reluctantly, "but they mistook me for someone else."

"If you weren't guilty why did you run?" Penny demanded suspiciously. "Why didn't you wait and explain?"

"You can't explain to a cop," the boy told her with a scornful curl of his lip. "You see, I have a juvenile court record—it doesn't amount to much but the police won't give me a chance. I've been trying to go straight, but every move I make they watch me."

"Tell me your name."

The boy hesitated, then said quietly:

"Jerry Barrows."

"I mean your real name," Penny smiled.

A telltale flush crept over the youth's face, but he threw back his head a trifle defiantly.

"It is my real name. I'm no thief either. I admit I've been in a little trouble before this, but today it wasn't my fault. Another fellow and myself were standing in a crowd when an old lady let out a holler that someone had picked her pocketbook. The police came running. They spotted me right off. I hadn't been near the old lady, but she was so excited she was ready to identify anyone. When the cops tried to arrest me on suspicion I took to my heels."

"What sort of juvenile court record do you have?" Penny asked.

"Nothing of consequence. Once I was in a gang that took some apples from a pushcart. It was done in fun, but the judge put me on probation on account of it."

Penny occasionally had visited juvenile court sessions and in many respects the stories she had heard there corresponded to Jerry Barrows' account of his difficulties. Yet in some ways his tale did not ring true. Obviously, he was trying to convey the impression that he had never had a chance and yet he wore expensive clothing. She suspected too that he had been educated in a school fully as good as the one she attended.

"I am sorry, but I must turn you over to the police," she told him. "I don't believe your story. It doesn't hang together."

A strange change came over the boy's face. The last trace of arrogance left him as he turned pleading eyes upon the two girls.

"I lied about my name," he admitted, "but I did it because I want to protect my mother. If she learns that I am in trouble again it will kill her. Please, won't you let me go free?"

Even as the boy spoke, his eyes were roving to the door. It would not be difficult for him to overpower the two girls and escape if he really chose.

"If I should let you go will you promise not to get into any more trouble?" Penny asked suddenly.

The boy nodded.

"I'll find a job and keep straight."

"Would you really work if you had a position?" Penny questioned.

"Would I? Just try me!"

"Then I'm going to turn you loose," she decided. "Come to my father's office tomorrow at nine o'clock. I'll ask him to help you find a position."

"Where is his office?" the boy inquired.

"In room 305 of the Leader building. You'll see his name on the door. Christopher Nichols."

"Nichols, the detective?" the boy questioned uneasily.

"Yes, but you needn't be afraid he'll turn you over to the police. Wait now, and I'll see if the coast is clear."

Opening the garage door a tiny crack, Penny peered out. As she had expected there were no officers lingering about the neighborhood.

"It's safe to leave," she informed.

He started away, then paused and offered his hand to Penny.

"Thanks for giving me a break," he told her gratefully. "I really meant what I said about going straight."

With that he darted through the open door and was lost in the night.

CHAPTER III

An Impulsive Act

"I don't know why I let him escape," Penny said self-accusingly as she closed the garage doors. "I simply did it on the impulse of the moment."

"One couldn't help liking the boy," Susan declared optimistically. "Do you suppose he'll keep his promise and come to see your father?"

"If he doesn't I'll know I made a silly mistake. I hope they can't put me in jail for permitting criminals to escape!"

"You might look very well in stripes," Susan teased. "They would never become me because I'm too plump."

Penny was in no mood to respond to the attempted banter.

"I wonder what Dad will say when he learns about it," she mused uncomfortably.

She did not have long to speculate for as the girls turned toward the house Mr. Nichols came down the walk.

"I can't get in at the front door," he complained good naturedly. "Has Mrs. Gallup locked up the place for the summer?"

Penny explained what had happened but as she repeated Jerry Barrows' story it sounded flat and a trifle ridiculous. She was not surprised that her father listened incredulously.

"Why were the police searching for the boy?" he questioned.

"I didn't learn," Penny confessed. "I have only the boy's word."

"And yet you expect me to find him a job?" Mr. Nichols demanded gruffly. "If he ever shows up—which he won't—I'll turn him over to the authorities."

"Oh, Dad, you wouldn't, not after I gave my promise that you'd help him!"

"Why should I assist you in thwarting justice?" Mr. Nichols questioned severely. Penny could not see that his eyes were twinkling. "Are you trying to ruin my reputation as a detective?"

"I didn't mean to do anything that might embarrass you, only I couldn't bear the thought of turning the boy over to the police. He was so young."

"I was only teasing," Mr. Nichols told her kindly. "If the boy does come to my office I'll have a talk with him."

"But you don't really think he'll come?"

"I have no way of knowing, Penny. I must admit I'll be rather surprised if he appears."

Penny relapsed into moody silence as she walked toward the house with Mr. Nichols and her chum. She had begun to regret her hasty action.

"I left your roadster at a downtown garage," Mr. Nichols commented, switching to a different subject. "I notified the police that the wheels had been stolen but I did not have time to see the insurance company. I can attend to it in the morning unless you care to do it yourself."

"I may as well," Penny agreed listlessly.

She was feeling very gloomy indeed. Although her father had refrained from blaming her, she knew that he was amused if not annoyed at her behavior. Above all else, she coveted his admiration.

"Cheer up," he said lightly as the three entered the house. "What if you did make a slight blunder? All detectives must learn by experience."

"A fine detective I'd make!" Penny sniffed. "I fail at the very first test. I'm just soft hearted I guess."

"Part of the blame should fall on me," Susan declared. "Jerry Barrows didn't seem in the least like a criminal, Mr. Nichols. I was impressed with his story too."

"I feel sure he must have been a very persuasive talker," the detective smiled. "However, I don't consider that either of you committed any great crime in permitting the boy to escape so I shouldn't worry about it now that the deed is done."

Mr. Nichols regarded the incident as closed, but Mrs. Gallup had heard enough of the conversation to surmise a little of what had happened. In response to her questions, the girls were forced to relate the entire story.

"Penelope Nichols, I never thought you'd do such a silly, foolhardy thing!" the housekeeper said severely. She felt it her privilege to be outspoken for she regarded the girl almost as a daughter. "Why, that young criminal might have killed you! And to think you let him get away without even making an effort to call the police!"

"I'm sorry about it now, Mrs. Gallup, but I thought I was acting for the best. Please, let's not talk about it any more this evening."

The subject had grown very painful to both Susan and Penny. They interested themselves in backgammon and as soon as they could do so gracefully, went to their bedroom.

"I'll never hear the last of it unless that boy shows up at father's office tomorrow," Penny groaned as she tumbled into bed. "I feel positively ill over the affair."

At breakfast the next morning she was her usual cheerful self. She even dared to hope that Jerry Barrows would keep his promise.

"You'll be at your office all morning, won't you, Dad?" she questioned anxiously.

"All morning," he repeated, smiling quizzically at her over his newspaper. "If your young friend calls upon me I'll telephone you."

Directly after breakfast Susan insisted that she must return home as her mother would be expecting her.

"I'll walk along with you," Penny offered. "I promised Father I'd stop at the insurance office this morning."

At the Altman residence the girls parted. Penny continued downtown alone. Mr. Nichols had furnished her with the address of the Reliance Insurance Company and she experienced no difficulty in locating the office.

After stating her mission she was ushered immediately into the presence of a portly gentleman who adjusted insurance claims. She was not surprised to learn that her name already was known to him.

"So you are Christopher Nichols' daughter?" the man remarked with interest. "We think very highly of your father here. In fact, his work has so impressed us that we have engaged him to assist us in stamping out this gang of auto accessory thieves. But of course you already know that."

"My father did mention something about it," Penny murmured.

"Of late the gang has been extending its activities," the adjuster went on, warming to his subject. "Why, last night alone, over thirty thefts of car wheels were reported to the police."

"Thirty!" Penny gasped. "And I imagined I was the only one to have such bad luck."

"Quite the contrary. You merely chanced to be one of the victims of a systematic combing of the city. Nearly all of the wheels were taken in a relatively small downtown area. Now, in all probability there will be a lull in the activities for a few weeks. Then the gang will make another large haul."

"But when the wheels are taken in such numbers I should think it would be easy to trace them," Penny ventured.

The adjuster shook his head.

"For the most part the wheels are trucked to other cities for disposal. The serial numbers are altered and the stolen goods is sold and distributed to dishonest dealers almost before the authorities are aware of the thefts. The police have been unable to cope with the situation." The adjuster smiled broadly, adding: "Now that your father is on the case, we're expecting a little action."

"I'm sure he'll provide it," Penny declared loyally.

The adjuster reached for a form book, and after asking a few routine questions concerning the stolen wheels, wrote out an order which permitted her to have them replaced free of charge at the garage where her roadster had been towed. Penny thanked him for the prompt service and left the office.

Since she was eager to have her car in operating condition with the least possible delay, she carried the order directly to the Hamilton garage. A courteous attendant promised that he would have the roadster equipped and ready for the road within a few minutes.

"You'll need a new standard for the spare too," he advised as she stood viewing the crippled car. "When the wheel was stolen, the thief didn't bother to take it off. Instead he cut the standard with some sharp instrument. Probably with a little hand power saw."

"Isn't that a new method?" Penny inquired with interest, walking around the car to view the severed pieces of metal.

"We're getting quite a few cars in here that way," the attendant returned as he unbolted the ruined tire standard and tossed it into a corner.

While the man fastened a new wheel upon the rack, Penny went over and curiously picked up the discarded scraps of metal. She noted the jagged marks which the saw had left.

"I wonder if Dad might not make use of this," she thought. "I'll take it along anyway."

Somewhat to the amusement of the garage man, she carefully placed the pieces of steel in the rear compartment of the car.

Penny had heard her father remark that many times it was possible to trace a crook by the tools he used. Once Mr. Nichols had apprehended a kidnapper by means of a ransom note which had been written upon a typewriter with a characteristic imprint. Penny hoped that the scraps of metal might upon scientific analysis disclose the type of instrument which had been employed by the thief to sever the tire standard.

"I'll drive directly to Dad's office and see if he can make use of any of these old pieces," she decided.

Although the errand provided an excellent excuse, the real purpose of her call was to learn if Jerry Barrows had kept his appointment.

Mr. Nichols was busy in the inner office when Penny arrived, but Miss Arrow, the efficient secretary, told her that she might go in. She found the detective engrossed in studying a group of photographs and their accompanying Bertillon records.

"Trying to brush up on who's out and why?" Penny asked banteringly.

Mr. Nichols nodded as he offered a photograph for her inspection.

"This is one of the men who I think may be involved in the automobile accessory thefts."

"Not a very pretty face," Penny commented.

"No, and 'Rap' Molberg hasn't a very pretty record either. He's served several terms in the pen, though usually he's a little too smart to have anything proven against him. Rap is the ringleader of the well known Molberg gang. It begins to look as if the outfit had extended its activities to Belton City."

"Is this Rap's description?" Penny inquired, indicating the Bertillon record which lay upon the desk. It consisted of a bewildering array of figures.

1.67.6 1.74.0 88.1 19.0 14-5
HGT OA TR HL HW

"Can you decipher it?" Mr. Nichols smiled.

"I know the HGT stands for height and TR for trunk, but what are the other abbreviations?"

"OA means outer arm," the detective explained. "HL represents head length and HW indicates the head width. Of course all the measurements are reduced to meters, centimeters, and millimeters."

"It looks complicated."

"Not after you become accustomed to it. For instance, I can see at a glance that Rap Molberg is five feet and seven-eighths inches tall—or as it appears in Bertillon—one meter, sixty-seven centimeters and six millimeters."

"I don't believe I'll ever care to be a detective," Penny smiled. "It's too much like studying the multiplication table!"

"Crime detection is a scientific profession——" Mr. Nichols began, but Penny cut him short.

"Tell me, did Jerry Barrows come to interview you this morning?"

"No, and I very much fear we'll never see the young man. I made a point of looking up his juvenile court record and find he has none."

"Then he must have given me a false name."

"I suspect he did, Penny."

"I guess it was silly of me to trust him. I didn't exactly believe his story at the time, and yet he seemed like a rather decent sort too."

"I'd not worry about it any more," Mr. Nichols said kindly.

"I'm afraid I've just done another foolish thing too," Penny declared. She then told him about the severed wheel rack.

"Why, I'd like to examine those pieces of metal," the detective said with interest. "What did you do with them?"

"They're in the roadster. I parked the car in front of the office."

"Then I'll just go down and get them," Mr. Nichols decided. "I should have inspected the car more carefully last night but I was in a hurry. Wait here and I'll be back in a minute."

During her father's absence, Penny amused herself by looking through some of the books on his desk. There were several weighty volumes devoted to criminology and law. She found them dull and turned with more interest to the photograph of Rap Molberg.

He had the appearance of a typical man from the underworld. His eyes were hard and glaring; there were sullen, cruel lines about his mouth. The only unusual mark of identification was a long jagged scar across his left cheek.

In the outside office, a telephone rang. Penny heard Miss Arrow answer the call. Apparently, the secretary was unaware that Mr. Nichols had stepped from the office, for she said:

"Just a minute, please. I will connect you with him."

An instant later the telephone at Penny's elbow jangled.

She took the receiver from its hook intending to explain to the caller that Mr. Nichols had left the office. Before she could speak, a cold, precise masculine voice came to her over the wire.

"Just a little warning, Mr. Nichols!" the words clipped into her ear. "Lay off the Molberg gang or else——"

Penny heard a receiver click. The wire had gone dead.

CHAPTER IV

The Molberg Gang

Penny signaled frantically for the operator's attention. It seemed minutes before the telephone girl responded mechanically: "Number please."

"I was disconnected with my party," Penny informed tensely. "See if you can trace the call. It is very important."

"Just a minute please."

There was another long wait, then the telephone operator informed Penny that the call could not be traced. It had been made from a pay station.

Mr. Nichols entered the office just as Penny hung up the phone.

"Anything wrong?" he asked quickly, noticing the expression on her face.

Penny repeated the warning message.

"Well, it looks as if I'm on the right trail," Mr. Nichols declared, not in the least disturbed. "I'd have preferred that the Molberg gang hadn't learned I was shadowing them, but such news travels fast through underground channels."

"I'm afraid some of those dreadful men may harm you," Penny said anxiously. "Promise me you'll be careful."

"I am always careful, my dear, but I refuse to go around wearing a bullet proof vest. This isn't the first warning telephone call I've received."

"I suppose not," Penny sighed. "But I should think that if the members of the Molberg gang know you have been assigned to the case, it would be hard to secure evidence against them."

"It won't be easy," the detective agreed. "However, I flatter myself that I have a few trained investigators whose activities will never be suspected."

"You mean they mingle with underworld characters and try to gain their confidence?"

"Yes, that's the usual plan. When I locate Rap Molberg I'll have him constantly shadowed."

"I've never seen many of your assistants around the office," Penny remarked.

"Naturally not," Mr. Nichols smiled. "If they came here to report, every crook in Belton City would be aware of it within an hour."

"Then how do you keep in touch with your men?" Penny asked curiously.

"There are a few secrets which I must keep to myself. Aren't you taking a rather sudden interest in my work, Penny?"

"Perhaps I am. Since my car wheels were stolen I feel personally concerned in the case. I wish I could do something to help."

Mr. Nichols became grave. "There is nothing you can do, Penny. The last thing in the world that I could wish would be to have you involved in the case. In fact I've been worried for fear——"

"For fear of what?" Penny demanded as her father checked himself.

"I've been afraid that the Molberg gang might attempt to strike at me through you. Until this case is finished you must be very careful."

"I'll be careful, although even for you I refuse to go around wearing a bullet proof vest," Penny grinned, paraphrasing his previous words. "Anyway, it might be exciting to be kidnapped."

"If you talk like that I see I must assign someone to keep watch over you."

"It won't be necessary," Penny assured him hastily. "I promise to stop, look and listen before I make any rash moves."

As if to demonstrate, she tiptoed to the door, opened it cautiously, peered forth at Miss Arrow who was busy at her typewriter, and then with a casual "goodbye" flung over her shoulder, was gone.

The following week was an uneventful one in the Nichols household. As was usually the way when Mr. Nichols became involved in an important case, meals were served at odd hours and often the detective did not come home at all for lunch or dinner. Penny complained that she never saw her father. Certainly she heard very little concerning the work he was doing for the insurance company.

On a Wednesday afternoon she was in the back yard washing her roadster with the garden hose when Susan Altman came running up to relate a bit of news.

"Penny, the most wonderful thing has happened!"

"What?"

"I'm to have a car for my birthday present!"

"Not really!"

"Yes, I am. I've been saving money for two years, but I never made much headway. Father always thought I was too young to have a car too until this summer."

"What made him change his mind?"

"Mother, I guess. You see she has to have the family car a great deal, but nothing would induce her to drive it herself. I'm to have the new automobile as my very own providing I take Mother wherever she wishes to go."

"That should be an easy condition to meet," Penny smiled. "What kind of car are you going to get?"

"I don't know yet. I thought perhaps you'd help me select it."

"I'd love to. After running this old bus for nearly three years I consider myself quite an authority on cars."

"I can buy any low priced model I wish," Susan went on enthusiastically. "What color shall I get?"

"One that doesn't show the dirt," Penny advised promptly as she coiled up the hose and put it away. "It seems to me that I spend half my time trying to keep this animal of mine presentable."

"I thought I might like blue," Susan ventured. "I don't suppose you'd have time to go with me now and look at a few models, would you?"

"Of course I'll go! Wait until I change into more presentable clothes."

Penny darted into the house, returning in a few minutes.

"Where are you going to buy your car?" she questioned.

"Father told me to go to the Brunner garage on Second Street."

"I'll drive you there in the roadster," Penny offered.

At the Brunner salesrooms a few minutes later the girls were greeted by the manager, George Brunner. He was a tall, thin man with sharp black eyes. When he spoke to his employees his manner was overbearing and haughty, but in the presence of the two girls he beamed and smiled and hung upon their words. He talked glibly as he piloted them from one shiny new car to another.

Presently Susan found herself hypnotized by a blue coupé. After Mr. Brunner had taken the girls a ride in a similar model, she whispered to Penny that she thought she would buy the car.

"Why don't you look around at a few other places first," Penny suggested. "You might make a better deal."

"I'm afraid to wait for fear Father will change his mind. Besides, this is exactly the type of car I like."

Penny refrained from saying more, but she was sorry that her chum seemed determined to make such a hasty transaction. For some reason she had taken an instant dislike to George Brunner. Susan, however, noticed nothing amiss in his manner and listened spellbound as he talked glowingly of the little blue coupé.

"I think I'll take it," Susan decided hesitatingly. "Could I drive it away?"

"Certainly," the manager beamed, steering her gently toward the inner office. "Just step inside and we'll fill out the necessary papers."

Almost before she was fully aware of what she was doing, Susan had written a check in payment for the car and had signed the usual legal papers.

"Do you think I've made an awful mistake?" she asked Penny nervously while they sat waiting for the car to be serviced.

"It's a beautiful model, Susan. And if it operates even half as well as Mr. Brunner claimed, it should be a wonderful bargain."

"You didn't like that man very well, did you?"

"No," Penny responded shortly.

"The Brunner garage is supposed to be one of the best in Belton City."

"I know it is. I haven't a thing against Mr. Brunner except that I don't care for his manners."

The discussion ended for the manager had returned to announce that the new car was ready to leave the garage.

"I am sure you will find it perfectly satisfactory, Miss Altman," he beamed. "But in the event that anything should go wrong don't hesitate to call upon us."

"I'll remember that," Susan said.

With Penny beside her to offer advice, she drove the coupé from the garage. Turning out into Second Street she narrowly missed being struck by a truck which was traveling at a high rate of speed.

"Better get out into the country until you've had an opportunity to become accustomed to handling the car," Penny suggested.

"That's a good idea," Susan agreed. "I don't want to wreck the thing before I drive it home."

After an hour of straight driving on a deserted road, she became quite dexterous at operating the gears. When she felt entirely confident of her ability to handle the car in any emergency, the girls drove back into the city. They parted at the Brunner garage where Penny had left her own roadster.

"Thanks for helping me select the car," Susan told her chum gratefully.

"I didn't have much to do with it," Penny smiled. "But it's a fine looking automobile. I wish I had one half as nice."

"I'll let you drive mine whenever you like," Susan offered generously.

When Penny reached home it was nearly dinner time. Mrs. Gallup was busy in the immaculate green and white kitchen, frosting an angel food cake.

"Any mail for me this afternoon?" Penny inquired, pausing to scrape up a generous spoonful of fudge from the frosting pan.

"I declare, I've been too busy all day to even think of the mail."

"I'll look."

Penny went to the box at the front door. There were three letters. Two for Mr. Nichols and one for herself. The latter was addressed in pencil on a cheap yellow envelope.

"Wonder who it's from?" she thought with interest.

Quickly, she ripped open the envelope, glancing at the signature which had been signed at the bottom of the brief note.

"Jerry Barrows!" she exclaimed.

Eagerly she read the message.

"Sorry I couldn't keep the appointment with Mr. Nichols," the boy had written. "Tell your father to be on guard. His life is in danger."

CHAPTER V

Penny Turns Sleuth

Mr. Nichols did not have a great deal to say regarding the note which Penny read to him later that evening at the dinner table.

"Don't let it worry you," he advised. "Just put it away for future reference and forget about it."

"Future reference?"

"Yes, it's always wise to keep such communications. One never knows when a sample of handwriting might prove useful."

"I'm sure Jerry Barrows must have some good qualities or he'd never have sent the message. Don't you think so, Dad?"

"Perhaps. It's obvious the boy was afraid to talk with me."

"But why should he warn you that your life is in danger? Do you think he could know anything concerning the Molberg gang?"

"It isn't likely, but he may have some underworld connection."

"I'm getting more nervous every day," Penny declared. "I'll never feel very easy until all the members of that gang are captured."

"It may be a more difficult task than I at first believed," her father remarked, frowning. "I know that Rap Molberg is hiding somewhere in the city but so far none of my investigators have been able to trace him."

"Perhaps he's through causing trouble," Penny said hopefully.

"He'll make enough when the time comes."

"I've not heard of any automobile thefts or anything of the sort for several days."

"That's just it. Things have been altogether too quiet. It's like a lull before the storm. A bad sign."

Mr. Nichols abruptly left the table. He walked to the door, then came back.

"I must go downtown again this evening, Penny," he said regretfully. "I'll leave the telephone number of my new office in the event you should need to reach me. It isn't listed in the 'phone book,' of course."

"Your new office?" Penny demanded. "What became of your old one, may I ask?"

"It's still there," Mr. Nichols smiled. "Miss Arrow has assumed charge, and I've taken up temporary quarters on the tenth floor of the Atler building."

"Isn't that almost directly across from the Brunner garage?"

"Yes, it's located in the downtown theater district. The bulk of the auto accessory thefts have taken place in this relatively small area. From the window of my new office I secure a bird's eye view of all that goes on in nearby streets."

"Surely you don't expect to catch the thieves in the act of stealing automobile wheels!" Penny marveled.

"It will be the surest way of gaining a conviction. If a professional crook isn't captured at the scene of his crime, he usually is clever enough to cover his tracks completely. An amateur is seldom so skillful in obliterating clues."

"May I visit this new office of yours?" Penny asked.

"Yes, if you use discretion and don't come too often. I have taken the office under an assumed name—John Bradford. I shouldn't care to have my real name known for awhile."

"I'll be very discreet if I come," Penny promised.

Her father turned to leave.

"It must be dull for you here alone at night," he said apologetically. "Why don't you take Susan to a picture show?"

"I think I'll do that," Penny agreed.

After Mr. Nichols had left the house, she telephoned Susan. Mrs. Altman answered the call, informing her that her daughter was spending the evening at the home of an aunt.

"I may as well go to the show alone," Penny decided.

One of her favorite movie stars was showing at a neighborhood theater only a few blocks from the Nichols home. Penny walked the short distance. She thoroughly enjoyed the picture, remaining to see part of it twice. It was a little after nine o'clock when she left the theater.

Recalling that Mrs. Gallup had requested her to bring home a pint of ice cream, she crossed the street to the nearest drug store.

While she was waiting to be served, a man in grimy workman's clothes slouched into the store. He pretended to interest himself in a cigarette slot machine, but Penny noticed that he darted furtive glances at the waiting customers.

Something about the man's appearance struck Penny as peculiar. She conceded that he looked like a day laborer yet his actions and mannerisms were not in keeping.

"I've seen him before," she thought.

Suddenly the picture of Rap Molberg flashed into her mind. Yet as she scrutinized the man a second time she could see only a slight resemblance to the photo her father had shown her.

However, as the man moved swiftly to the nearest telephone booth, suspicion began to take root. In identifying underworld characters, photographs were never a certain guide, that Penny knew. Too often a criminal disguised his appearance. Not by false wigs and beards which even a novice detective might note at a glance. Rather by altering his features or by adopting costumes commonly seen upon the street.

Impulsively, Penny stepped into a telephone booth adjoining the one which the workman had entered. By leaning close to the wooden panel, she could hear part of the conversation.

"That you, Jake?" he asked gruffly. "Everything's set for the big haul. We're all ready to go ahead whenever the boss gives the word."

By this time Penny was almost certain that she was listening to the voice of Rap Molberg. Although in general the man did not resemble the photo which she had seen, the color of his eyes and the expression of his mouth were identical. His build seemed to correspond to the figures of the Bertillon record.

A minute later the man slammed down the telephone receiver and left the booth. Penny waited until he was out of the store, then dropped a nickle in the slot. She called the number which her father had given her. There was no response at the other end of the line.

"I suppose he's left the office," she thought frantically. "Oh, I can't let that man get away."

She rushed from the drug store and reached the street just in time to see the workman disappear around a corner.

"I wonder if I dare attempt to shadow him?" Penny debated.

She was a little afraid, yet the streets in the immediate vicinity of the theater were well lighted, and it did not seem too dangerous.

Turning the corner, she caught sight of the man far ahead. He was walking rapidly. She too quickened her step, but took care not to approach close enough to arouse his suspicion.

Presently the man paused beside a fine looking automobile which had been parked at the curbing. As he glanced sharply up and down the street, Penny pretended to be looking into the window of a jewelry store. Actually, she was watching the man's reflection in the glass.

She saw him step into the car, take a key from his pocket and turn on the ignition. As he drove away, Penny quickly noted down the license number.

She glanced hopefully up the street but there was no policeman within sight. A taxi cab driver noticing her agitated expression, cruised close to the curb. Penny hailed him.

"Follow that green car ahead," she directed tersely, climbing in. "Don't let it get out of your sight."

At the first corner they were held up by a light which was changing from caution yellow to red. Risking arrest, the taxi driver crashed it.

The green car ahead had picked up speed. It weaved in and out of traffic in a dangerous manner, driven by a man who was both skillful and reckless.

The pursuit led into the hilly, crooked streets upon which the older section of Belton City had been built. As they raced down first one narrow street and then another, turning corners at a breathless speed, Penny suspected that the man had become aware that he was being followed. Her driver had increasing difficulty in keeping him in sight.

"The right hand turn!" Penny cried as the taxi-man hesitated at an intersection.

They tore down a dark, twisting street at a break-neck speed. Suddenly the driver slammed on his brakes. The thoroughfare had come to an abrupt end.

"It's a dead-end," the taximan said in disgust, turning the cab around. "He couldn't have come this way."

"I'm sure he did," Penny insisted.

The street was short and she could see its entire length. The green car had vanished.

There were no houses or garages into which the automobile might have turned. On either side of the street stood factory and manufacturing buildings.

"Shall I try another road?" the driver questioned.

"It's no use now. I guess we've lost him. But I was positive that man came this way. I don't see how I lost him."

She gave her home address to the driver, and sank back against the cushions, completely disgusted with the turn of events.

As Penny alighted at her own door, she cast a speculative glance toward the lighted window. If her father had not returned, Mrs. Gallup was almost certain to ask embarrassing questions concerning her arrival in a taxicab.

"And I forgot the ice cream too!" she thought. "I'll have a nice time explaining."

However, it was not necessary to give an account of her activities. Mrs. Gallup met her at the door.

"You came just in time, Penny. You're wanted on the telephone."

"It isn't Father?"

"No," the housekeeper assured her, "I think it's your chum."

"Susan?"

"Yes." Mrs. Gallup pushed her gently toward the telephone. "The girl seems to be greatly excited over something. Do hurry and answer for she's been waiting several minutes now."

CHAPTER VI

Susan's Misfortune

When Penny answered the telephone she heard her chum's agitated voice.

"I know I shouldn't bother you so late in the evening," Susan began excitedly, "but I've had the worst luck with my new car!"

"You haven't been in a collision?"

"No, it isn't quite that bad. But I'm stranded on Eighth Avenue and I can't reach my folks by telephone."

"I'll drive over and get you," Penny offered. "What's the matter anyway? Has the engine balked already?"

"The car has been stripped by thieves! I'm so furious I can't even talk about it."

"I'll come right over and see for myself," Penny declared.

Pausing only long enough to tell Mrs. Gallup where she was going, Penny backed her roadster from the garage. She located Susan not far from Eighth Avenue and Clark, sitting gloomily behind the wheel of her new coupé.

As Penny drove up she saw that the spare wheel was missing. A spotlight was gone and likewise a reflecting mirror.

"The thieves very obligingly left me the steering wheel," Susan greeted her friend. "When a person can't park fifteen minutes without having everything stolen, I think it's time for the police to get busy!"

"How did you happen to be parked downtown?" Penny inquired. "Your mother said you had gone to visit an aunt."

"I did, but on the way home I stopped at the "Y" for a swim. I should have left the car on a lot but I thought I'd save the quarter. Now witness the result!"

"You still have four tires," Penny pointed out. "That's more than they left me."

"Yes, but they've done something to the engine. It won't start. That's why I called you."

Penny lifted the hood to look at the motor. Susan peered anxiously over her shoulder.

"Can you tell what's wrong?"

"It looks to me as if some of the vital parts are missing. Offhand I'd say it was the generator."

"What's a generator?" Susan asked blankly. "Are they very expensive?"

"I don't know but I imagine they are. Isn't your car covered by insurance, Susan?"

"No, it isn't. We intended to take it out but we didn't think a few days' delay would make any difference."

"Thieves seem to favor new cars."

"I realize that now," Susan said ruefully. "You know, I noticed a rather queer thing as I came out of the "Y." A garage service car was standing beside my coupé. It drove away as I came toward it."'

"A service car?" Penny demanded alertly. "Did you see what garage it was from?"

"No, I didn't. In fact, I scarcely paid any attention at the time for it wasn't until I had reached my car that I realized it had been stripped."

"You must have surprised the thieves in the act!" Penny said excitedly. "Undoubtedly, they are using the service truck as a front to escape detection."

"How do you mean?"

"Why, they drive up in the truck and pretend to be changing a tire or repairing the engine. Passersby notice nothing amiss."

"But what if the owner appears?"

"They drive away or if actually caught claim that they have made a mistake in identifying the car of a customer."

"The driver of the garage truck did act suspiciously," Susan admitted. "I was stupid not to jot down the license number."

The girls were talking so earnestly that they failed to note the approach of a policeman. He paused to see what was wrong.

"Wheel stolen?" he asked, surveying the car critically.

"The wheel, the generator, and almost everything detachable," Susan informed. "I was only gone a few minutes too."

"Have you reported to headquarters?"

Susan shook her head.

"What's the use?"

"You might recover your stolen property," the policeman said optimistically, taking a notebook from his pocket. "Your name and address?"

Susan gave it and furnished such information as she could regarding the theft.

"Your car wasn't the only one that was stripped in this neighborhood tonight," the officer told her. "Not fifteen minutes ago I ran into a similar case."

"I think it's time the police did something about it," Susan said somewhat crossly.

"We're up against a tough gang, Miss. Our force is small and we can't place a man on every street corner."

As the officer continued to make out his report, a girl came running toward the little group. She was about Penny's age, though much thinner. Her black hair blew in the wind, unrestrained by hat or beret.

"Oh, Father!" she cried in agitation.

The policeman turned quickly around.

"Why, Betty, what brings you here?" he questioned in surprise.

"I've been following you for two blocks," the girl said breathlessly. "I wanted to——"

Her voice trailed off. She had noticed Susan and Penny.

Slowly her eyes swept over the dismantled car, then they roved to her father with an expression which was akin to panic.

"What was it you wanted, Betty?" he asked.

"It doesn't matter now," she stammered. She added tensely: "Father, you're not making out a report!"

"Certainly, I am."

"Don't do it," the girl pleaded, gripping his arm. "You know what it may mean. Please, for my sake!"

Penny and Susan exchanged a quick glance. They were at a loss to understand the girl's strange attitude. Why should she be so troubled because her father was writing out a routine report of a theft?

To their relief, the policeman laughed carelessly and went on making out the report.

"You're hysterical, Betty," he accused. "Come, get a grip upon yourself."

"I'm sorry," the girl murmured, glancing nervously at Penny and Susan. "I shouldn't have made such a request."

"My daughter is very excitable," the officer said apologetically. "She didn't really mean what she said."

There was an awkward pause. Penny turned to the girl and questioned kindly:

"Haven't I seen you somewhere? Your face is familiar."

"I've watched you swim at the Y.W.C.A. pool. You dive beautifully too."

"Oh, I remember you now! But I don't know your name."

"I am Betty Davis. You've already met my father."

"Jerome Davis," the officer added. "Just a sidewalk pounder."

The girls smiled at the disparaging remark. Penny mentioned her own name.

"You're not related to Christopher Nichols?" the officer asked.

"Yes, I am his daughter."

"You don't say! Well, I am glad to make your acquaintance. Down at the station they think a lot of your father."

"He was on the force many years ago, I believe," Penny said politely.

"That was before my time, but I'm always hearing about him. He's solved some difficult cases that have baffled our best detectives."

Penny made a perfunctory response and the officer turned to his daughter.

"Betty, you shouldn't be out alone so late at night. You must go back home at once."

"If you live nearby I'll be glad to take you in my car," Penny offered.

"I shouldn't like to trouble you," the girl said hastily. "My home is only a few blocks away."

"It will be no trouble at all," Penny insisted, opening the door of her roadster. "Do let me give you a lift."

The girl flashed her father an appealing glance. It was obvious to both Penny and Susan that she was greatly upset about something, yet the officer appeared not to notice. He did not seem to realize that she wished to speak with him privately.

"It's very kind of you to take my daughter home, Miss Nichols," he said quietly. "Don't keep them waiting, Betty."

Reluctantly, the girl crowded into the seat beside Penny and Susan.

"I live at 1406 St. Clair Avenue," she informed briefly.

As they drove slowly along, Penny had an opportunity to study the girl. She was an odd type. Serious and certainly not talkative. When drawn into conversation, her answers were given in monosyllables.

"She's worrying over something," Penny thought.

The car halted before a modest brown cottage on St. Clair Avenue. Betty Davis alighted.

"Thank you so much for bringing me home," she told Penny gratefully. She hesitated, then added earnestly: "I know you thought it queer because I asked my father not to make that report."

"I'm sure you must have had a very good reason," Penny returned.

"I was overwrought or I shouldn't have made the request. You see, my father is in great danger!"

"I don't quite understand."

Already Betty Davis felt that she was revealing too much.

"I wish I could tell you about it—but I don't dare," she murmured.

With that she turned and ran into the house.

CHAPTER VII

An Awkward Situation

"Now just what did she mean by that remark?" Susan demanded of her chum as they saw Betty Davis disappear inside the cottage.

"I'm not a mind reader," Penny returned with a shrug. "The air seems to be filled with mysteries this evening."

She then told of her experience in shadowing the man whom she had believed to be Rap Molberg. Susan listened in amazement.

"You must have lost your senses, Penny Nichols! If you turn up missing some morning, it will be easy to guess the reason why!"

"Perhaps it was a foolish thing to do. But I thought if I could learn Rap Molberg's hideout it would be a big help to Dad. Investigators from the agency have been searching days for that man.

"You should leave the job to them then," Susan advised severely.

"I guess I will," Penny said ruefully. "At any rate, I failed at it."

After dropping Susan off at the Altman residence, she drove on to her own home. Mr. Nichols was nervously pacing the living room floor when Penny entered.

"I'm glad you're here," he said in relief. "Mrs. Gallup told me you had gone off after receiving a telephone call. I was afraid it might have been a frame-up."

"I went to meet Susan. Didn't Mrs. Gallup explain?"

"No, but it doesn't matter now. I shouldn't have worried only things have been popping in the city tonight."

"The tire theft gang is at work again?"

"Yes, they made a big haul. When the story gets out, the Nichols Detective Agency isn't going to appear in a very good light."

"You haven't been working long on the case, Dad."

"True, but to date the result of our investigation has been disappointing. This haul tonight has all the earmarks of Rap Molberg's hand, yet my men can find no trace of him in the city."

Penny could not restrain her news an instant longer. She half expected that her father would scold her for the taxicab escapade, but to her surprise he became mildly excited.

"Can you give me an accurate description of the man, Penny?"

"He was about five and a half feet in height and wore workman's clothes."

"Undoubtedly, a disguise," the detective interposed.

"His eyes were dark. The expression of his mouth was sullen. His teeth were uneven."

"Did you notice a scar on his cheek?"

"No."

"The mark isn't really significant, for Rap Molberg would be clever enough to hide it. Did you observe anything more?"

"He seemed extremely nervous. And the telephone conversation made me suspicious. Oh, yes, when he drove away I copied down the license number."

"Let me see it," Mr. Nichols said eagerly.

She handed it to him.

"Penny, you've done a fine piece of work," he praised.

"But I let him get away."

"You couldn't help that. This license number may make it possible for us to trace him. I'll telephone police headquarters right now and see if they know anything about the car."

He sought a telephone in an adjoining room. Penny lingered by his elbow while he made the call. After talking for some minutes, he hung up the receiver.

"I was afraid we might run into this, Penny. The license number which you noted down belongs to a stolen car."

"Then it won't be of any use to you."

"Probably not a great deal. But don't feel disappointed. It wasn't your fault that the man got away. He has eluded some very clever investigators."

"I had another queer experience when I went to meet Susan," Penny related. "Did you ever hear of a policeman by the name of Jerome Davis?"

"Yes, why?"

Briefly, Penny told of her meeting with the officer and his daughter.

"I can't comprehend why Betty tried to prevent her father from writing out a report of the theft, Dad. If such information leaked out it might cost him his position on the force."

"I can readily understand that," Mr. Nichols returned. "Jerome Davis is in a bad spot already."

"Just how do you mean?"

"In the first place, he has never stooped to play politics. Some of his superiors dislike him on that account, although until recently they never questioned his honesty."

"Has anything ever been proven against him?"

"No, but he has been subjected to severe criticism because so many auto accessory thefts have occurred in his district. The situation gives his enemies a fine opportunity to shoot at him."

"I suppose that explains why Betty didn't want him to report another theft. She was afraid it might cost him his job."

"That might be the reason."

"It won't be fair if they discharge him on account of something he can't prevent."

"Life isn't always fair, Penny."

"What do you think about Jerome Davis, Dad? Is it your opinion that he is honest?"

"Yes, I think he is." Mr. Nichols abruptly arose. "What you have told me is very interesting, Penny. I believe I'll call Davis to the house and have a talk with him. He should be off duty soon."

Telephoning the Davis home, the detective left a message that the policeman was to call back at his earliest convenience.

"It's too late to get him here tonight," Mr. Nichols remarked to his daughter. "If he does telephone I'll ask him to come to my office to-morrow."

"Then I won't hear what he has to say," Penny complained.

"I'm afraid you wouldn't anyway, my dear. Mr. Davis would never talk freely if you were present at the interview."

"I suppose not—if he knew it. But I might hide in the closet."

"That would be a trifle too theatrical for my taste, Penny."

The doorbell rang sharply. Mrs. Gallup came from another room to answer it. A moment later she returned to the study where Mr. Nichols and Penny were sitting.

"Mr. Davis to see you," she told the detective.

"Davis? Strange he didn't telephone before coming at such a late hour. But of course I'll see him."

Reluctantly, Penny arose.

"I suppose I'll have to go."

"No, wait. You really want to hear the interview?"

"I most certainly do."

"You've earned the right," Mr. Nichols smiled. "Sit over there in the high-back wing chair."

Deftly he turned it so that the tall back faced the door. As Penny sat down he placed a book in her hands and advised her to curl her feet up under her as she often did when she read. In such a position, she was completely screened from the gaze of the caller as he entered the room.

No sooner had Penny settled herself comfortably than Mrs. Gallup ushered the officer into the study. She then quietly withdrew.

"Have a chair," Mr. Nichols invited cordially. He offered one which would not reveal Penny's hiding place.

"My daughter told me you had telephoned," Jerome Davis began a trifle uneasily. "I thought I might as well walk on over and see you. I hope I didn't come too late."

"Not at all. I seldom retire before midnight. Davis, I suppose you wonder why I wanted to talk with you."

A grim look had come over the officer's face.

"I judge it's about the stolen wheel and generator. I met your daughter this evening."

"So she told me. However, what I really wanted to talk to you about was the Molberg gang."

The officer offered no response.

"I don't need to tell you that they are at the bottom of this recent outburst of thievery," the detective went on, eyeing his caller shrewdly. "Unless they're captured soon, you'll be in a bad spot, Davis."

"I'm in one now. I've always tried to be honest and do my duty as I saw it. Because of that I'll probably end up without a job."

"Not if you team along with me and help me to capture this gang. I'll say frankly that since I took this case for the insurance company, I haven't had much cooperation from the police."

"I'll be glad to help you all I can, Mr. Nichols. But I must act cautiously."

"You mean for fear of antagonizing your superiors?"

"Yes, that's the chief reason," Jerome Davis admitted hesitatingly.

"Have you another?" Mr. Nichols probed.

"It's this way," the officer informed, growing confidential. "The commissioner seems to think that I've sold out to Rap Molberg. At least he appears to suspect that I serve as a stool pigeon for the gang, and tip them off as to the best time to pull a job. I've been demoted twice. A self-respecting man would have resigned long ago."

"Unless he wanted to prove the truth," Mr. Nichols suggested softly.

"That's it," the officer agreed. "I mean to hang on until I'm fired from the force. I've been unlucky because so many jobs have been pulled in my district. I'm working on the case when I'm off duty and one of these days I may get a break."

"You spoke of working cautiously. Are you afraid to have your superiors know what you are about?"

"Not exactly. You see, Mr. Nichols, lately I've been running down a few tips regarding the whereabouts of Rap Molberg. Some of his henchmen have given me a polite warning to mind my own affairs. Their threats have terrified my daughter, and my son, Jimmie."

"Then you don't feel that you can push the search?" the detective inquired pointedly.

"I intend to go on just as I have," Jerome Davis maintained firmly. "I expect to do everything in my power to capture Rap Molberg!"

"Good!" Mr. Nichols exclaimed. "I am satisfied that you are the sort of man I can use. If you will work secretly with my investigators, I am confident we shall produce results."

"I'll be glad to cooperate in every way I can," the officer promised.

They shook hands to seal the agreement. Jerome Davis turned to leave.

"Thank you for coming here tonight," the detective said as he escorted the officer to the door. "You will receive instructions from me within a short while. A day or two at the latest."

After the door had closed behind the caller, Penny arose from her chair.

"Did you enjoy the interview?" her father asked, smiling.

"It was vastly exciting! I thought surely I'd be seen."

"Mr. Davis was too engrossed in our talk to be very observing."

"I don't wonder that Betty Davis worries about her father. I heard him say that he had been threatened by the Molberg gang."

"Yes, Davis is in an awkward situation. However, he seems to be a man of courage. I can use him."

"I'll be glad when you're through with this case," Penny sighed. "I'm worried sick for fear something may happen to you. All these threats——"

"Forget them," Mr. Nichols advised. "I've received plenty of them before this and I'm still alive."

"But Rap Molberg——"

"Forget him too," the detective smiled. "Unless you do, I'll be sorry I ever told you about the case. Run along to bed now—and pleasant dreams."

"Nightmares to you!" Penny retorted.

She slowly mounted the stairs and disappeared into her own room.

CHAPTER VIII

A Revealing Clue

For the next few days Penny saw very little of her father. He left the house early in the morning and often did not return at night until after she had retired. Meals became something of an ordeal, for either Mr. Nichols buried himself in a newspaper or allowed the conversation to lapse.

"You're as talkative as the sphinx!" Penny accused. "Is the case going badly?"

"Not to my knowledge."

"Is it going well then?"

"Not especially."

"Have you found any clue as to the whereabouts of Rap Molberg?"

"Not yet."

"You're impossible!" Penny cried furiously. "It's no use trying to learn a thing from you unless you're in exactly the right mood!"

In desperation she sought solace in the companionship of her chum, Susan. They attended a great many moving picture shows and developed an enviable tan by swimming outdoors and playing tennis for hours at a time.

Although Penny was permitted complete freedom, Mr. Nichols had warned her to use caution whenever she left the house at night. On more than one occasion in going downtown or to the home of a friend, she half suspected that she was being followed.

She refrained from mentioning her fear to Mr. Nichols lest he curtail her freedom. But she became more alert and watchful.

One afternoon while Penny was mowing the yard, Susan drove up in her coupé. It was the first time she had used it since the unfortunate night of the theft. She hailed Penny joyously.

"The old bus is traveling again! It has a new generator and a fine new wheel!"

Penny inspected the new purchases.

"See anything wrong with the wheel?" Susan demanded.

"Not a thing. Why?"

"I bought it for about half the regular price. I was a little afraid I might have been gipped."

Penny examined the spare wheel more critically. "It looks exactly like the one Dad bought me some time ago for nine ninety-eight. In fact, I'd think it was the same tire—the one that was stolen from me—if I didn't know better."

"I only paid four dollars," Susan informed proudly. "Wasn't it a bargain?"

"It looks like it. Where did you buy the tire?"

"Oh, at a little place on South Lake Street. I don't remember the name."

"South Lake isn't such a good location," Penny said thoughtfully, "I've heard Father say that a great many disreputable firms operate there. I know once he traced stolen furniture to a dealer on that street."

"I hope I didn't buy a stolen wheel," Susan declared. "Was that what you had in mind, Penny?"

"I thought of it right off. But I haven't any reason for saying it. For all I know, your tire may be a legitimate bargain."

"I wish there was some way of finding out for certain," Susan said anxiously.

"Let's look for the serial number. The wheel should have one."

Penny moved closer to inspect the new purchase.

"The number is here all right," she acknowledged.

"Then the tire wasn't stolen," Susan said in relief.

Penny shook her head. "I'm not so sure of that, Sue. It looks to me as if these numbers have been changed. Wait a minute!"

She darted into the house, returning with her father's magnifying glass. Using it to study the figures upon the wheel, the girls could plainly see that the numbers had been altered.

"To think I'd buy a stolen wheel!" Susan exclaimed indignantly. "I'm going right back and tell that dealer a thing or two!"

"You can't very well do that. We would be in no position to prove anything."

"I suppose you're right," Susan admitted.

"I'd like to see the establishment where you bought the tire," Penny said after a moment's pause. "Could you point it out to me?"

"Yes, I'll take you there now if you like."

Penny rolled the lawn mower into the garage and climbed into the coupé beside her chum.

"How do you like your car by this time?" she inquired as they drove toward South Lake Street.

"Not so well. It starts hard and has a funny sound in the engine. In a few days I mean to take it back to the Brunner garage for a complete overhaul."

South Lake Street was located in the poorer section of Belton City. The neighborhood was noted for its second-hand stores and it was said that sooner or later stolen merchandise found its way into the crowded little shops which lined the narrow thoroughfare. Often wares were piled upon the sidewalks to attract an unwary buyer. Stoves, cheap tables, and all manner of hardware rubbed elbows with clever brass jugs, imported vases and Oriental rugs.

Presently, Susan halted her car in front of a tire shop which was located at the outskirts of "second hand" row.

"This is the place," she announced.

The owner of the shop, a short, squat little man with beady black eyes, stood at the window. He eyed the girls sharply.

"Shall we go in?" Susan asked.

"Let's, but we mustn't act as if we suspect anything."

Assuming a casual attitude, they sauntered into the shop. The dealer recognized Susan instantly. On her first visit he had been a trifle too cordial, but now he regarded her shrewdly.

"Something?" he inquired.

"My friend wishes to buy a new wheel," Susan informed. "She'd like to see one like I bought yesterday."

Again the dealer cast a sharp glance at Penny.

"Haven't I seen you in here before?" he asked.

Penny shook her head. "No, this is the first time I ever came into your store."

"I've seen you somewhere," the man muttered. "Now, I know! You're Christopher Nichols' daughter!" He pronounced the name of the detective with a slight sneer.

"Yes, I am," Penny acknowledged reluctantly. "But I'm sure I've never seen you before."

"That's quite likely."

"Then how did you know me?"

"That's my business," the dealer retorted shortly. "I am sorry, but I can't do business with you. Good day."

Penny stood her ground.

"Haven't you any tires for sale?"

"Not for you, I haven't. You're a snooper just like your father! Get out of here!"

Penny would have carried the argument further, but Susan tugged at her sleeve. They hastily left the shop. As they drove away, they saw the dealer standing at the plate glass window, watching.

"Such a horrible man!" Susan gasped. "I was actually afraid of him. What made him act like that?"

"I think he must have guessed why we came," Penny told her. "As a sleuth I seem to be a walking advertisement of my calling!"

"He recognized you the minute you stepped into the store. Didn't that strike you as queer?"

"Yes, it did, Susan. I'm almost certain that man is dealing in stolen tires. He's probably afraid of the law. It's to his advantage to recognize plain clothesmen and persons who might cause him trouble, I imagine I've been seen with my father."

"I should think the police could arrest him."

"It isn't as easy as one might believe, Susan. If a fence is caught with stolen merchandise he claims to have purchased it in good faith. Actually he has taken it off the hands of some thief. An arrest is hard to make."

"Then there's nothing we can do?"

"I don't know. I'll ask Father when he comes home tonight."

"I think a fence is even more contemptible than a thief," Susan said scornfully. "I'd give anything if I hadn't bought that tire."

"I'm glad you did," Penny smiled, "for the clue we gained may prove useful to Father."

The girls were relieved when they reached the end of South Lake and turned into a more pleasant street. Driving toward their homes they relapsed into a long silence, each absorbed in her own thoughts. There were occasions when the two friends talked frantically for hours. There were other times when they would speak scarcely a word, yet enjoy perfect understanding.

Penny had slumped in her seat. Suddenly, she straightened, her eyes riveted upon a pedestrian who was crossing the street in front of the coupé.

"Susan, isn't that Jerry Barrows?" she demanded excitedly.

The car swerved wildly as Susan turned to look.

"It is!" she exclaimed.

"Stop the car," Penny pleaded. "I want to talk with him."

Susan brought the coupé to a halt at the curbing. Penny sprang out.

"Jerry Barrows!" she called.

The boy wheeled and saw her. He hesitated an instant, then turned and ran.

CHAPTER IX

A Trap

"Wait! I want to talk with you!" Penny called.

The boy paid no heed. As she ran after him he darted into the nearest alley.

Provoked, Penny hastened back to the car where Susan was waiting.

"Let's try to catch him," she proposed, springing in beside her chum.

Susan turned the coupé in the narrow street and drove into the alley. They could see the boy only a short distance ahead.

"We'll overtake him," Penny cried jubilantly.

Aware that he was being pursued, the boy ran faster. Then noticing an opening between two buildings, he squeezed through it and was lost to view.

Penny tried to follow afoot but soon gave it up. She returned to the coupé disheartened.

"He eluded us this time, Sue. I suppose that boy thought I meant to have him arrested. Actually, I only wanted to question him."

For some twenty-five minutes the girls cruised around the block, hoping to sight Jerry Barrows again. Although they kept close watch of the alleys he did not reappear.

"Did you notice anything peculiar about that boy's appearance?" Penny inquired as they turned toward home.

"No, why?"

"He was dressed much better than on that night when we caught him in our garage. He doesn't look as if he had ever had much hard luck."

"I imagine his entire story was a lie," Susan declared. "He didn't keep his promise to call at your father's office, and now he runs like a coward when we try to talk with him."

"I don't see how I was taken in so easily," Penny confessed ruefully. "I couldn't help liking the boy. I hoped he would turn over a new leaf."

Alighting at the Nichols home, she invited her chum to remain for dinner.

"I can't tonight," Susan told her regretfully. "We're having guests."

"I suppose I'll have to eat alone then. No use expecting Dad home."

In this she was mistaken. Entering the house, she discovered Mr. Nichols submerged in his favorite easy chair.

"I didn't look for you home so early, Dad."

"Nor did I expect to make it when I left the house this morning. However, I must return to the office immediately after dinner."

"Is it so very important?" Penny demanded.

Her father smiled.

"Lonesome?"

"Not exactly, only the evenings seem so long."

"Why don't you go to a moving picture show?"

"I've seen every good one in town. Besides, I'm tired of movies."

"I realize I am being a very poor father," Mr. Nichols acknowledged, reaching over to squeeze her hand. "You might come back to the office with me."

"I'd like that," Penny said instantly.

"It will be very dull," her father warned.

Directly after dinner, they motored to Mr. Nichols new office opposite the Brunner garage. Since the detective expected to occupy it only a few weeks at the most, it was equipped with the barest of necessities. There was a battered desk, three chairs and two telephones. Nothing more.

"What in the world do you do here?" Penny questioned.

"Mostly sit and wait," the detective admitted. "I receive reports from some of my men here. During the day I watch the street."

With a wave of his hand he indicated a powerful field glass which lay upon the desk.

Penny picked it up, training it upon the Brunner garage on the opposite side of the street.

"Why, it brings everything remarkably close! Do you sit here at the window and watch for the auto thieves?"

"Something like that. We've set a trap."

"A trap?" Penny was all interest.

"Yes, we've planted several expensive new cars in key positions on the street. Our men are secretly watching them, of course. We hope that the auto thieves will select one of our models to strip."

"It must be tedious waiting."

"It is, but if we catch the gang our patience will have been rewarded."

"But what of Rap Molberg?" Penny questioned doubtfully. "Surely he must delegate the actual thievery to others."

"I'm not so sure," Mr. Nichols said slowly. "It wouldn't surprise me to learn that Molberg acts upon orders from someone higher up. However that may be, if we capture some of the lesser fry, they can be made to talk."

The detective busied himself at his desk. For a time Penny amused herself by watching pedestrians through the field glass. Growing tired of that, she buried herself in a magazine. It was not very interesting. By nine o'clock she was thoroughly bored.

"I think I'll go home," she announced. "I don't believe anything exciting will happen tonight."

"So that's why you came," her father chided. "And I thought it was because you craved my company!"

"I did, but this bare office is too depressing."

"Then I'll excuse you," Mr. Nichols smiled. "Take a taxi home if you like."

"No, I think I'll walk."

It was a pleasant mellow evening and Penny was in the mood for a long stroll. She chose a roundabout route home.

She was absent-mindedly crossing a street, thinking of nothing in particular, when an automobile without headlights shot past her at a high rate of speed. Frightened, Penny sprang backwards.

"The nerve of that driver!" she thought. "He missed me by inches."

She watched the car swerve around a corner and race up a dead-end street.

"Why, this is the very place where I lost track of Rap Molberg!" she told herself.

She rushed to the corner. Her fascinated gaze followed the retreating automobile. It tore madly to the end of the street where it abruptly halted.

Penny lost sight of it for an instant. Then to her surprise, the headlights were flashed on. In the reflected light she saw the tall walls of a large manufacturing plant.

The beam was turned off again. Darkness swallowed up the car.

While she was straining to see, Penny heard the shrill blast of a warning siren from far up the street. The next instant, a police radio cruiser shot past.

With a loud screaming of brakes, the police car came to a stop not far from Penny.

"Did you see an automobile without headlights come this way?" the driver asked tersely.

Penny was only too glad to offer information.

"It turned into this dead-end," she began.

The officers did not wait to hear more. With a roar, the cruiser was off again. It reached the end of the street and halted because it could go no farther.

Penny, bent upon missing nothing, followed as fast as she could.

By the time she reached the radio cruiser one of the officers had alighted. He was looking carefully about. Sighting Penny, he walked over to her.

"Say you! I thought you told us that car came this way."

"It did," Penny maintained staunchly. "I saw it go to the very end of this street. The lights flashed on for an instant. Then the car seemed to vanish. I think it must have gone into that building."

She indicated the Hamilton Manufacturing Plant. The officer surveyed it briefly.

"Don't kid me!" he snapped. "Only a Houdini ever went through solid walls!"

He climbed back into the police car, saying gruffly to the driver: "Get going, Philips. It was a wrong steer. We must have missed that car at the turn."

Penny waited until the cruiser disappeared around the corner. Then she crossed the street and stood staring meditatively at the tall walls of the Hamilton Plant. There was no doorway leading into the building.

"It's uncanny," she murmured. "Yet I know very well that car went in there some way." The building was entirely dark. There were no windows on the street side. Only a vast expanse of unbroken wall.

"It's too dark to see anything tonight," Penny decided after a brief hesitation. "Tomorrow I'll come back and perhaps make a few interesting discoveries!"

And with that resolution, she turned and walked rapidly toward home.

CHAPTER X

The Vanishing Car

Penny fully intended to tell her father of her experience, but she retired before he came home. She overslept the next morning. When she descended to the breakfast room at nine o'clock, Mrs. Gallup told her that the detective had been gone for nearly an hour.

"Your father wasn't in a very good mood this morning," the housekeeper informed as she served Penny with a steaming hot waffle. "He complained about the coffee. When he does that it's always because something's gone wrong with his work."

"You mustn't mind Dad," Penny smiled. "We couldn't get along without you."

Mrs. Gallup sniffed.

"I do the best I can. The coffee does taste all right, doesn't it?"

"It's perfect."

"When your father's working on a hard case he always likes it strong as lye," the housekeeper complained. "But I know he was worried about something this morning."

"What makes you think so?"

"I heard him muttering to himself. Something about the stupidity of the police. It seems they let some crook get away last night after your father had laid careful plans to catch him."

"Not Rap Molberg?"

"I think that was the name. Mr. Nichols didn't tell me anything, I just heard him talking it over with himself."

"It's the only person he will discuss his business with," Penny chuckled.

After Mrs. Gallup had gone back into the kitchen she mulled over the information which the housekeeper had given her. It struck her as probable that the car which she had seen vanish down the dead-end street had been driven by Rap Molberg or one of his confederates.

"I wish I could have talked with Dad about it before he left the house," she thought.

Penny had not forgotten her resolution to visit the Hamilton Plant by daylight. As soon as she had helped Mrs. Gallup with the dishes, she left the house, walking directly to the scene of the previous evening's adventure.

The street was deserted. No one questioned her actions as she made a careful inspection of the old building which had housed the Hamilton Manufacturing Company until its failure. She examined the walls inch by inch, but although she was convinced it was there, she could find no hidden entrance.

Regardless of her failure to find evidence, Penny was unwilling to give up her original theory. She remained unshaken in her belief that the mysterious automobile had disappeared into the Hamilton building.

"There's no other place it could have gone," she reasoned. "I'll talk it over with Dad and see what he thinks."

When she stopped at his office, Mr. Nichols was not there nor could Miss Arrow tell her when he might return.

The detective did not come home for luncheon and late in the afternoon telephoned to say that he would take dinner downtown. Rather than spend an evening alone Penny called Susan, arranging that they should go to the library together.

The girls spent an hour in the reading room, but for some reason Penny could not interest herself in the magazines. She kept turning through them and laying them aside. She felt unusually restless.

Presently an electrical magazine attracted her attention. She glanced over it carelessly until she came to a particular article which dealt with photo-electric cells and the clever purposes for which they were used.

"Why, these 'magic-eyes' are almost human," she commented in an undertone to Susan. "They turn lights on and off, cook meals, and open doors, when a beam of light strikes the cell——"

"I've heard of them before," Susan interrupted in a tone which clearly implied that she was not in the least interested.

Penny took the hint and dropped the subject. But she became absorbed in the article. When she closed the magazine a half hour later, her face was flushed with excitement.

"Susan, let's get away from here," she proposed in a whisper. "I've just had an inspiration!"

Grumbling a little at being forced to leave a fascinating story before she had finished it, Susan followed her friend from the building.

"What about this inspiration of yours?" she demanded as they walked to Penny's parked roadster.

"It's this way, Susan. I knew there was a logical explanation for the mysterious disappearance of that car Rap Molberg was driving. Let's go over to the Hamilton Factory this minute and test out my new theory."

"You may know what you're talking about, but I'm sure I don't, Penny Nichols."

"That's because you wouldn't let me tell you about that article I was reading," Penny laughed. "But I'll explain everything as we go along."

Without pausing to consider that it might not be safe to investigate the abandoned manufacturing plant at such a late hour, the girls drove directly into the hilly section of Belton City. Penny turned into the familiar dead-end street and was relieved to find no sign of other vehicles.

She halted her roadster at the very end of the pavement in such a position that the bright headlights played upon the massive walls of the Hamilton building.

"It must be located higher up," Penny murmured to herself.

"What is?" Susan demanded. "I don't see what you're about anyway."

Without answering, Penny directed the beam of her spotlight upon the stone structure. Inch by inch she moved it systematically over the high wall.

"Perhaps it's only a silly idea," she acknowledged at last, "but I believe that somewhere in the wall there must be a secret door—one mechanically operated. No doubt the outline of the opening is disguised by the many irregular cracks in the masonry."

"If you're looking for a secret opening, why not come in the daytime when you can see much better?"

"I've been here in the daytime and the door can't be detected—at least not by the eye. I'm hoping to have better luck this time."

"I can't for the life of me see how," Susan began, but ended with a startled gasp.

A portion of the massive wall was slowly moving backward.

"Just as I thought!" Penny chuckled in delight. "Now we know how Rap Molberg escaped from the police the other night."

In fascination the girls watched the widening gap in the wall. Soon it was large enough for an automobile to easily drive through into the empty building.

"How did you open it?" Susan asked in awe.

"The beam of my spotlight struck a photo-electric cell which was secreted near the eaves," Penny explained briefly. "You should have read about it at the library."

"I wish I had now. It's almost uncanny."

"Let's drive in and have a look at the inside," Penny suggested daringly.

"Won't it be dangerous?" Susan demurred.

"The place seems to be deserted. But probably it would be wiser if you waited here and I went in alone."

"No, if you're going to risk it, so am I!"

"Then here goes," Penny said.

She drove the roadster through the opening into what appeared to be an empty room. Curiously, the girls glanced about. Suddenly Susan uttered a stifled scream.

"The door! It's closing!"

Already the opening had narrowed to a mere slit. It was too late to retreat.

"Don't lose your nerve," Penny advised, although her own heart was beating at a furious rate. "We'll find some way to open that door."

"Someone may have seen us drive in and closed it deliberately!"

"I don't think so, Susan. It must have closed automatically."

"Anyway, we're prisoners inside this horrible place! We'll starve to death before anyone will suspect we're here!"

"I got you into this and I'll get you out," Penny announced firmly. "There must be some button or lever that opens the door from the inside."

Although the headlights of the roadster illuminated a portion of the large room, many of the corners and crannies remained dark. Taking her flashlight from the pocket of the car, Penny moved cautiously about searching for some means of escape. Susan remained huddled in her seat, too terrified to move.

Penny examined the door, but it would not budge when she threw her weight against it. She could find no lock or catch.

There were several windows high overhead but without a ladder she could not hope to reach them. She was growing more disturbed than she cared to admit, when Susan called to her.

"Penny, I think there's some sort of lever over here by the car."

Penny flashed her beam in that direction and was relieved to see that her chum was right.

"It must operate the door, Susan! We should be out of here in a jiffy!"

Confidently, she grasped the long handle and pulled with all her strength upon the iron lever.

From below came the low rumble of moving machinery. Penny and Susan riveted their eyes hopefully upon the door. It did not open.

Instead, a square of floor upon which the roadster was resting, slowly began to sink.

Uttering a frightened scream, Susan tried to open the car door.

"Save me!" she cried frantically.

Penny leaped nimbly down upon the running board.

"It's all right," she laughed shakily. "We're only descending in an elevator."

"We'll be killed before we ever get out of this dreadful place!"

The elevator struck the lower floor with a gentle thud. Penny then climbed into the car and drove it a few feet forward. Relieved of its weight the platform slowly rose again until it had resumed its former position.

"We're worse off now than we were before," Susan moaned.

"I think this must be the way out," Penny comforted.

She indicated a tunnel-like opening directly ahead. Susan who had been looking in the opposite direction had noticed a small room which appeared to be an office. She called her chum's attention to it. Together, they cautiously peered inside.

Save for a battered desk and several chairs the tiny room was empty. Cigarette ashes and old papers were scattered over the floor, giving evidence that the office had been used recently. Penny tried the desk and found it locked.

She picked up a few scraps of paper from the floor. They were without interest.

A folded newspaper lying upon one of the chairs drew her attention. Opening it, she noticed that an article on the front page had been underscored with pencil lines. The headline read:

"AUTO ACCESSORY THEFTS
ON STEADY INCREASE HERE"

The story hinted that Belton City police had been unable to cope with the situation and that local insurance companies long harassed by an organized gang, had turned the case over to private detectives.

Above the latter statement someone had written the name of Christopher Nichols in pencil.

Penny carefully folded the newspaper, replacing it upon the chair exactly as she had found it.

"Let's get away from here before we're caught," she urged. "I suspect we're in a Molberg hideout."

"Nothing would please me better than to leave this place," Susan retorted grimly. "Just lead me to an exit."

"I think the tunnel probably will take us out. Come on, let's see."

Returning to the roadster the dark passage seemed forbiddingly dangerous. Carefully examining the concrete floor, Penny discovered tire patterns in the dirt. Other cars had used the tunnel.

With the engine at idling speed, they drove into it. The tunnel led downward at such a steep angle that soon Penny was forced to use her brakes to keep from going too fast.

"Where will this thing end?" Susan asked.

Even as she spoke they reached level ground. An ordinary double garage door barred the way. Susan sprang out to open it.

"Why, we're in an empty garage," she announced as she swung back the door.

Penny drove the roadster through and waited until Susan had closed the door behind her. Through a plateglass window the girls could now see the street. But it took them some time to locate another unlocked door which permitted them to escape.

Once safely out of the building, they pulled up at the side of the road to take note of their surroundings. At first they could not imagine where they were.

"Why, this must be Arlington Avenue," Penny decided. "We're several hundred feet lower than we were when we left that dead-end street on the hilltop!"

"What a clever means for a crook to escape a police chase!"

"Yes, isn't it? I'm almost certain the place has been used by the Molberg gang."

"Then we can't get away from here too quick," Susan declared nervously.

Penny laughed.

"We're safe enough now. Besides, I imagine this escape is never used except in an emergency—probably only when the police are hot on the trail."

Susan glanced at her watch.

"It's after ten o'clock and I promised mother I'd be back at nine."

"I'll take you straight home," Penny promised. "I don't suppose I need to mention it, but I think we shouldn't tell anyone about what we discovered tonight. At least not until the police have been notified."

"Of course not," Susan agreed instantly. "Why don't you have your father make the report for us?"

"I'd like to handle it that way, if you don't mind," Penny said eagerly.

"Then let's leave it that way. Aside from Mr. Nichols we'll not tell a soul about our discovery tonight."

A few minutes later the girls took leave of each other. Penny continued alone toward her own home.

Turning a corner in one of the outlying neighborhood business sections, she noticed a girl in blue hurrying along the street. Recognizing Betty Davis, Penny halted her roadster at the curbing.

The girl did not notice for she had paused to stare into the window of a café. A group of young men could be seen within, laughing and talking.

It was not the type of place frequented by women, and Penny was astonished when the girl started to open the door. But with her hand on the knob, Betty Davis seemed to reconsider, for she turned and walked rapidly away.

Penny drew alongside in her roadster.

"Going my way?" she asked cheerfully. "I'll be glad to give you a lift."

CHAPTER XI

A Threat

Betty Davis wheeled quickly about. She laughed to cover her confusion.

"Why, Miss Nichols! How you startled me!"

"I didn't mean to do that," Penny smiled. "If you're on your way home, can't I take you there in my car?"

The girl hesitated, and involuntarily, her eyes wandered toward the café. Then she stepped into the car.

"It's very kind of you to take me home, Miss Nichols. I'm not out alone this late in the evening as a rule, but something important came up. I searching for my brother."

"Jimmie?"

"Yes, how did you know?"

"I think your father mentioned his name."

"He didn't say anything about——" Betty broke off, finishing with an embarrassed laugh: "but then I know he didn't."

"Your father only mentioned that he had a son by that name," Penny said, eyeing her companion curiously.

"Jimmie is a good boy but he's caused father a great deal of worry," Betty added, feeling that some explanation was required. "Lately he's fallen in with bad companions."

"That is a pity," Penny murmured. "You mentioned that you were looking for him. Can't I help you?"

"Oh, no," Betty told her hastily, "I don't think I'll bother after all."

Penny permitted the matter to drop but she was not mistaken in suspecting that the reason her companion had decided to give up the search was because she already had located her brother at the café.

"Won't you come in for a few minutes?" Betty urged when the car stopped at her door. "Father isn't due home until late tonight and I'm all alone."

"I might stop a little while," Penny agreed.

Despite Betty's somewhat queer actions, she had liked the girl from the very first, and was eager to become better acquainted.

The Davis home was modestly furnished, yet with excellent taste. Penny could not refrain from referring to the clever color scheme which had been carried out so successfully in the living room.

"I'm glad you like it," Betty smiled. "You see, I'm studying to be an interior decorator."

"Why, how interesting."

"I attend night school," Betty explained. "Or rather I did. Just now Father is a little pressed for money so I've given it up for a few months."

"I hope you'll be able to go on with it again."

"Yes, so do I, for it's the one ambition of my life. I think after Jimmie is a little older it will be easier. Just now he's at the age where he feels he must have fine clothes and plenty of spending money."

"Perhaps you're too indulgent a sister," Penny smiled.

"Jimmie is only a year younger than I," Betty explained, "but since Mother died five years ago, I've always felt responsible for him. Lately I've been terribly worried."

"On account of the company he keeps?"

"Yes, that and other things." Betty arose and nervously crossed over to the fireplace. "I don't mean to unburden myself upon you, but lately Jimmie has been doing wild things. Father doesn't half suspect the truth. I'm half sick with trying to decide if I should tell him or not."

"Probably it would relieve your mind if you did," Penny advised kindly.

"Yes, but Father has always taken such pride in Jimmie. I can't bear to hurt him."

"Perhaps he could bring your brother to his senses."

"I'm afraid it may be almost too late. Jimmie is so headstrong. He won't listen to anyone. He's changed so much the last few months."

"It seems to me that your father should know the truth," Penny said quietly.

Betty Davis' face had grown slightly pale.

"I realize I should tell him," she acknowledged, "but I can't. There's a special reason why—don't ask me to explain." Abruptly, she tried to change the subject, saying lightly: "My brother is very handsome, I think. Would you care to see his photograph?"

"Indeed I would," Penny returned politely.

She waited while Betty went into an adjoining room after it. As the girl returned, a car was driving slowly past the house.

"That must be Father," Betty declared, moving toward the window.

Penny heard the automobile halt at the curbing. The next instant a hard object crashed through the windowpane, dropping with a thud at Betty's feet. Almost by a miracle she had escaped being struck by the flying splinters of glass.

Penny sprang to her feet, rushing to the door. She caught only a fleeting glimpse of the retreating car.

Betty was staring at a piece of paper which lay upon the carpet. It had been wrapped around a small stone.

"You read it," she begged Penny. "I'm afraid."

Penny reached down and picked it up. The message had been printed on cheap brown wrapping paper. It bore the warning:

"JEROME DAVIS, THIS IS THE LAST
WARNING YOU WILL RECEIVE FROM US.
WE GIVE YOU TWENTY-FOUR HOURS TO
CHANGE YOUR MIND."

"It's a threat from the Molberg gang!" Betty declared tensely as Penny finished reading the message aloud. "Oh, I'll never feel easy again until every member of that outfit has been placed behind bars! What do you think they will do when Father defies them?"

"Probably nothing," Penny comforted. "Most anonymous notes are sent by cowards and the threats seldom carried out. At least Dad doesn't regard them very seriously. He's been threatened by the Molberg gang too."

"And have they made no attempt to harm him?" Betty asked.

"Not to my knowledge. Dad seems more than able to look after himself, and I'm certain your father knows how to protect himself too."

"He should," Betty admitted. "He's one of the best marksmen on the police force."

"Then I think Rap Molberg is the one who should be on his guard," Penny smiled.

By making light of the threatening note she tried to relieve Betty of anxiety. Her efforts were not very successful. When she left the house a half hour later the girl was still excited and overwrought.

Not until Penny was nearly home did it occur to her that she had forgotten to look at the photograph of Jimmie Davis.

"Oh, well, it doesn't matter," she thought.

As she drove the roadster into the garage, Mrs. Gallup came down the path to meet her.

"I'm sorry to be so late," Penny said quickly before the housekeeper could take her to task. "A million and one things detained me. Dad's home, I suppose?"

"No, he isn't. But someone has been trying to get you on the telephone for the past hour."

"Probably it was Dad."

"It may have been, but it didn't sound like his voice. Listen, isn't that the phone now?"

They could hear the bell ringing inside the house. Penny ran to answer it. As she took down the receiver, she was greeted by a masculine voice. But it was not the detective who had telephoned.

"Is this Miss Nichols?" she was asked.

"Yes," Penny returned quietly, aware from the other's tone that she must prepare herself for bad news.

"Don't be alarmed, Miss Nichols, but your father has been hurt."

"Oh! Badly?"

"We're not sure yet. He is still unconscious. Can you come at once?"

"Yes, yes, of course! Which hospital?"

"He has been taken to a private home."

"Then tell me how to get there."

"It won't be necessary. A taxi has already been sent for you. It should be there by this time."

"I'll be waiting," Penny promised.

She hung up the receiver and turned to the housekeeper who was hovering anxiously at her elbow.

"Dad's been hurt," she said tersely to hide her emotion. "I don't know how badly for I couldn't learn the details. I must go to him at once."

"Oh, you poor thing," Mrs. Gallup swept the trembling girl into her arms.

They clung to one another for an instant, then Penny resolutely brushed away her tears.

"It probably isn't as bad as we fear," she said hopefully.

Catching up her pocketbook from the table, she hurried out upon the porch to wait for the taxicab.

CHAPTER XII

Kidnapped

As a dark colored cab stopped in front of the Nichols residence, Penny ran to the curbing before the driver could alight.

"You were sent here to take me to my father?" she asked.

"Yes, Miss."

The driver kept his head lowered so that Penny could not see his face clearly, but she was too troubled to notice anything wrong.

"Is Father badly hurt?" she questioned anxiously.

"I can't tell you, Miss. I was only told to come here for you."

The driver opened the door, and Penny stepped into the car. They sped away.

Presently Penny noticed that the taxi man seemed to be avoiding the main streets of the city. She thought little of it until she chanced to catch a glimpse of the driver's face in the mirror. She had never viewed such a hardened countenance. The man appeared to be watching her every move. It gave her a sudden chill.

"Where is my father?" she questioned abruptly.

"At a house out in the country," the driver returned gruffly.

"I didn't even know that he had left the city," Penny said suspiciously. "Tell me, how was he injured?"

"I don't know any of the details. You'll have to wait until you get there."

Penny leaned back against the cushions, to all appearances, reassured. Actually, she was terrified. The conviction was steadily growing in her mind that she had been the victim of treachery. She was almost certain that she was being kidnapped. How decidedly stupid she had been to walk into such a trap!

Penny felt actually sick as she considered the possible consequence of falling into the hands of the Molberg gang. It was not for herself that she feared but for her father. She knew him well enough to realize that he would sacrifice everything to be assured of her safety.

"If I let on that I suspect something is wrong it will only put the driver on his guard," she thought. "My best chance is to act innocent and watch for an opportunity to jump out of the car."

Already they were speeding along a dark, country road. On either side, the highway was lined with tall maples and oak trees. Houses were few and far between.

Penny tried to make careful mental note of the route they were taking from the city. It was difficult to distinguish objects for they were traveling rapidly.

As they turned into a bumpy, winding narrow road which led up a steep hill, Penny's uneasiness increased. From the manner in which the driver surveyed the roadside, she guessed that the wild ride was nearly ended.

"It's now or never," she told herself grimly.

The car had slowed down for the hill. Watching her chance, Penny made a sudden dive for the door. It was locked.