A SINGLE CLEW

THE home of Thomas Sutton was located in an old residential district of upper Manhattan.

It was after two o’clock when Cardona arrived there, accompanied by Commissioner Weston and Professor Biscayne. He found two persons in the house.

One was a policeman, ordered stationed there by Cardona. The other was Richard Sutton, son of the dead executive.

Richard Sutton led the way to the upstairs room, where his father’s body lay. There were no signs of foul play. It appeared to be purely an accidental death. But the three investigators thought otherwise, although they did not express their opinion to Richard Sutton.

“Tell me all about it,” said Cardona.

“Father and I lived alone, here,” said Richard, in a tired, choked voice. “It was his custom to go out every day, and to return after dinner. I suppose he did that yesterday.

“When I came in at midnight, I saw nothing amiss. I supposed that my father had retired.

“This morning I arose late. There was no sign of father. I supposed that he had gone out. I looked in his room. The bed was untouched. He had not slept there last night.

“I phoned a few places where I thought he might have stayed. He had not been seen.

“I called the police. A man came over here. We decided to search the house. We found no signs of anything being wrong.

“Somehow, we overlooked the closet under the stairs. At last we happened to open it. There we found my father’s body.”

Richard led the way downstairs, and the investigators examined the closet. The door was tight fitting. It had no knob; simply a latch on the outside. The door was closed.

Cardona opened it, and turned his flashlight into the interior. The closet was long, but the ceiling slanted downward, to a small shelf at the end.

While the detective was standing in the opening, something bumped against him. It was the door, closing of its own accord. Cardona stepped back.

Released, the door moved slowly, gathered speed, and shut with a slam. The latch clicked.

“So that’s it!” exclaimed the detective. “Thomas Sutton went into the closet; the door closed while he was there; he was trapped.”

Richard Sutton nodded soberly.

Cardona looked at the young man with a slight tendency toward suspicion. Richard Sutton was evidently broken by his father’s death.

The affair looked like an unfortunate accident. But the coincidence of the initialed letter — the third that had fitted in with circumstances — was too important to ignore.

Cardona began another inspection of the closet. He let the door shut with himself inside. He rapped against the barrier and called.

The noise was well muffled. Biscayne turned the latch, and Cardona emerged.

“Not much chance of any one hearing calls for help,” was the professor’s comment. Weston nodded.

“The closet is empty,” observed Cardona.

“Yes,” said Richard Sutton. “We used it only to store old books. The house was painted about six months ago. I took the books upstairs, and never brought them down.

“Years ago, my brothers and myself used to keep our bicycles and sleds in there. The closet has never served any purpose since except for the books, which are no longer there.”

“Was the door always this way?” quizzed Cardona.

“Yes,” said Richard. “There used to be a hook on the outside — on the baseboard. The screw eye is still on the closet door.

“The hook was broken off a long while ago, and we never replaced it. The painters removed it entirely.”

“Why do you think your father went in there?” asked Cardona.

“I don’t know,” said Richard. “That’s the only thing that puzzles me. I cannot understand why he should have entered the closet.”

THE whole case was perplexing. On the face of it, Thomas Sutton had simply decided to look into the closet under the stairs.

He had neglected to put something against the door to hold it open. That brought up an important point. Again, Cardona questioned Richard.

“Did your father know that the door would close in this manner?” asked the detective.

“I don’t think so,” responded Richard. “He might have noticed it once or twice, but I scarcely think that it would have registered with him. He was very absent-minded at times.

“Although rather methodical, he only paid attention to matters that directly concerned his thoughts of the moment. I feel sure that he had some definite reason for entering the closet, and therefore paid no attention to the door.

“If he had ever noticed it, his mind was so concerned with his specific errand that he forgot completely about the lock.”

Cardona looked in the closet again, and sniffed the smell of the fresh paint. He examined the bottom of the door, and saw that there was virtually no opening between it and the floor when the door was shut.

“Usually,” said the detective, “one should be able to obtain air in a closet like this. It is rather surprising that Sutton should have suffocated so easily.”

“How often has the closet been opened since it was painted?” questioned Biscayne, turning to Richard Sutton.

“I don’t recall that it was opened at all,” said the young man. “I may be wrong on that point. It may have been opened once or twice.”

“Then don’t forget the fresh paint,” said Biscayne to Cardona.

“Why?” asked the detective, in surprise.

“Fresh paint,” said the professor, “frequently produces carbon monoxide. That has been discovered recently.

“It was observed that men were taken sick while working in the freshly painted holds of ships. The cause was traced to the presence of carbon monoxide.”

“I never knew that,” exclaimed Cardona. “It seems impossible that this closet could be saturated with that deadly gas.”

“Not saturated,” corrected Biscayne. “But the fumes are probably present to a noticeable degree. That can be tested.

“Carbon monoxide is odorless. The presence of a limited quantity of the gas would account for a fairly rapid death of a person confined in the closet.”

“We have a death,” declared Cardona. “From what you have just said, professor, it is quite explainable as an accident.

“We must consider now if any one forced Thomas Sutton into that closet.”

“We searched the house for my father,” said Richard Sutton. “We found no traces of any one having been here.

“If my father met with foul play, I am keenly desirous of knowing it. But I have seen no indication.”

“What about your father’s financial affairs?” questioned Cardona bluntly.

“He was living on a pension,” replied Richard. “Until a few months ago, he still had some wealth. But father had a failing in that he took great interest in speculative enterprises.

“He was constantly investing in gold mines, oil wells, and new inventions of doubtful value. The last of these failed recently, and he had nothing left except this house and his retirement income.”

“Insurance?” asked Cardona.

“It was all in endowments,” said Richard. “They all matured, and the money went into the enterprises that I have mentioned.

“Father was generous. He made gifts to myself and my brothers. While he was no longer wealthy, his pension was more than sufficient for his present needs. Father was quite satisfied with life.”

“Did he have any enemies?”

“I AM positive that he had none. Of course” — Richard became reminiscent — “he dealt with unscrupulous speculators and fanatical inventors.

“He did have a few run-ins with people over money matters. But those occurred a long while ago — nothing within the past year; and they all concerned money that he had considered spending.

“Since he exhausted his resources, there were no occurrences of that nature.”

“Do you recall any definite incidents?”

“Not to a marked degree. I remember that a man visited father about two years ago, and they had a heated argument in the little living room upstairs. I heard the discussion through the doorway.

“The man wanted money for something, and claimed that father was trying to learn too much before he gave financial support. I do not know the nature of the matter.”

“What persons came here recently?”

“Only a few friends and acquaintances. How many, I do not know. They generally came on evenings when I was out.

“Father mentioned that he had occasional visitors, but he never brought up names.”

“I wonder,” said Cardona, “if any one was here last night. Let’s look around the place.”

At Richard Sutton’s suggestion, they went upstairs to the little living room. They found a check book in Thomas Sutton’s desk. The stubs, marked with initials and abbreviations, referred to small amounts.

There were a few letters and other items of correspondence. These offered no real clew.

HERE was a case that seemed totally devoid of pertinent facts. The only person who could have come under suspicion was Richard Sutton. He knew that the door of the downstairs closet would close and latch of its own accord.

Richard Sutton appeared to be an upright young man. His statements had been direct, and were given without hesitation. They were the kind of statements that could be checked in detail.

The son of Thomas Sutton must be innocent, Cardona felt, although the methodical detective intended to obtain statements from the other sons whom Richard had mentioned.

The task at hand was to search for anything that might show that some one had been here last night, or any evidence to the effect that Thomas Sutton had been influenced to enter the death trap.

The peaceful nature of the old man’s demise clearly indicated the possibilities of the master hand that had engineered the deaths of Silas Harshaw and Louis Glenn.

But this crime — if crime it was — seemed more perplexing than either of the other two.

Peering under the desk, Cardona spied a wastebasket and brought it forth. He saw a few papers in it. They proved to be printed circulars.

The detective shook his head as he looked at Roger Biscayne. Then he replaced the wastebasket.

As he did so, Cardona spied something on the floor beneath the desk. In another moment, the detective had stooped, and was exhibiting two crumpled objects — one an envelope, the other a sheet of paper.

Unfolding the paper, Cardona spread it upon the desk. With Biscayne peering over his shoulder, Cardona pointed quickly to the characters that appeared upon the crumpled sheet.

There were words there — typed in letters identical with those that had appeared in the death messages:

DEAR SUTTON: YOU WILL FIND YOUR GOLD-HEADED CANE ON THE SHELF OF THE CLOSET UNDER YOUR FRONT STAIRS. DANA.

Eagerly, Cardona swung toward Richard Sutton, who was standing at the other side of the room.

“Did your father have a gold-headed cane?” questioned the detective.

“Yes,” said Richard, in surprise. “He lost it a few months ago. He prized it very highly; it was a gift from a very dear friend.”

“Who is Dana?” asked Cardona.

“Roy Dana is an old friend of my father’s,” answered Richard. “One of my father’s best friends, in fact. He is a retired attorney, who lives in New Jersey.

“I called him before you came, to tell him of my father’s death. I learned that he went to Florida, two days ago.”

CARDONA was looking at the envelope. He noted that it was different from those which had contained the death messages.

The address was not typed. It was written in a rather shaky scrawl. But the postmark indicated the same office as the other letters.

“It was mailed two nights ago,” said Cardona to Biscayne.

“In between the death messages,” responded the professor.

“Yes,” said the detective. “The post office paid no attention to it, because it was not addressed to police headquarters.

“It may have come in yesterday morning’s delivery — perhaps not until yesterday afternoon.”

“That is more likely,” said Biscayne.

Richard Sutton had approached to look at the letter.

“If that came yesterday,” he said, “I doubt that my father would have opened it until last night.”

“Why?”

“Because he made it a practice to look in the mail box when he came home in the evening. I never use this address — I get all my mail at the club. What does the letter say?”

Cardona showed the message to Richard.

“Dana never sent that,” said the young man emphatically. “But I don’t think the fact would have registered itself with my father.

“Any statement of where the cane might be, would have caused him to act without question. That lost cane had become an obsession with him.”

“Why don’t you think Dana sent it?” asked Cardona.

Richard rummaged in the desk and brought out a greeting card that Cardona had tossed aside as unimportant.

It was addressed to Thomas Sutton, and was signed “Roy.”

“There is Dana’s handwriting,” stated Richard. “Firm — not shaky. I always admired the old man’s penmanship.”

Cardona nodded in agreement. He looked at Biscayne, then at Commissioner Weston, who was standing by with anxious eyes.

Then the detective stood erect and faced Richard Sutton.

“Sutton,” he said, “your father was murdered! Yes, murdered — not by any one who entered here, but by the man who sent this message.

“It led Thomas Sutton to the closet; it caused him to enter there with only one thought — to look on that shelf at the back. The door closed upon the unfortunate victim just as effectively as if some one had stood there to push it shut!

“Perhaps you have read of two deaths in the newspapers — Silas Harshaw and Louis Glenn.

“We have been notified of a third death. It has occurred. The murderer chose your father as victim.

“I have already given information to the newspapers. I am going to tell them that your father, too, was murdered.

“We cannot afford to neglect a single chance. Outside of the death messages, this letter is all that we have.

“But it is different. The others were received after death had struck. This one came before death.” The detective tapped the note with his forefinger. “This is the weapon which killed Thomas Sutton!”

Cardona turned to meet the commending eyes of Commissioner Ralph Weston. Professor Roger Biscayne was nodding his full approval of Cardona’s explanation.

A tenseness seemed suddenly to grip the room. For all three of the investigators knew that they were dealing with a supermind of crime — a slayer whose methods were as ingenious as they were deadly.

Three men had died. Their deaths had been announced. Would there be a fourth? That was the dread question menacing them at this instant. And the only way to thwart the murderer was to trace him through his own messages!