A man stopped at the side entrance of the County National Bank. He rang a bell, and waited until the metal door was unclosed. He was facing a watchman, who stood with gun in hand, The watchman's flashlight beamed upon the visitor's face.

"Hello, Mr. Salisbury," said the watchman.

He slipped his revolver back into its holster, and nudged over his shoulder with his right hand.

"He's in there," said the watchman, in a low voice. "Waiting for you, Mr. Salisbury." The heavy door closed behind the men. The watchman led the way into the main room of the bank. It was dark, and Salisbury pressed the watchman's arm. A man was approaching through the gloom.

"Leave us in here," said Salisbury. "We want to look around a bit and talk together, alone. Understand?"

"Yes, sir," said the watchman. "Mr. Delmar told me that." As the watchman started back toward the corridor that led to the side door, Hubert Salisbury advanced to meet the approaching man.

They spoke to each other in whispers; then Salisbury conducted the other to a small office at the side. Here, he turned on a light and sat down at a desk, facing his companion.

Hubert Salisbury was a clean-cut chap, not more than twenty-five years of age, although his poise and businesslike look marked him as a mature man.

Hubert's companion — Wellington — was considerably older. He seemed to be a rather slow and dull-witted individual; but that was affected. An experienced investigator, Wellington knew the value of self-effacement. Alone, with Salisbury, he quickly dropped his sluggish attitude.

"You've found something?" questioned Salisbury.

"Yes," declared Wellington. "At least, I think I have. I figured this whole proposition, Mr. Salisbury. That watchman of yours makes his rounds on a rather methodical sort of schedule. It wouldn't be difficult to slip one over on him — provided that you knew his ways. Now there's only one method that could be used to get a line on him. That's to be in here, keeping a watch of your own."

"It sounds logical," nodded Salisbury.

"Well," said the investigator, "the dough has been grabbed at night. Whoever has been doing it has been mighty clever. Studied the vault and been looking over the whole lay. No ordinary crook."

"So I've been laying here, on watch myself. More than that, I've been figuring how it would be possible to get in here."

"I can't say I've had any luck except that I've picked the one place where it might work. Downstairs, where all the safe-deposit vaults are located. That's where I want to look."

"But that's impossible!" exclaimed Salisbury. "That was built as a strongroom — right in the foundations of the building. You're wrong, there, Wellington—"

"I'm not saying I'm right," interrupted the investigator. "I'm only saying that I've studied this place from the bottom up. There's nobody here outside of Mr. Delmar and yourself that could know enough about the place to slide in and out. I've eliminated the employees.

"I work this way: a thing is being done. How could it be done? Well, in this case, the only system is in and out by some mighty clever method. Finally I hit the idea that the places that look the weakest might be the strongest; and the places that looked the strongest might be the weakest." The man's tone was convincing. While Salisbury appeared doubtful, he was, nevertheless, forced to agree that Wellington might be logical in his assumption.

"You think that someone," began Salisbury, "has direct access here—"

"I think more than that," interposed Wellington. "I think that this whole place is a running ground. I figure that some crook — maybe more than one — is so sure of himself that he can walk in and out of here any time he pleases.

"I wouldn't be surprised if a guy should walk in here right now and poke an automatic under our noses!" Salisbury shifted uneasily. The idea sounded fantastic; nevertheless, it was cause for alarm. He looked toward the door of the little office.

With unfeigned apprehension, he arose and opened the door. He looked into the big dark room. Perhaps Wellington was right. Salisbury almost fancied that he could discern a stealthy figure moving through the gloom.

"What do you propose to do?" he questioned.

"Start a search together," rejoined Wellington promptly. "I don't want to do it alone. I can't call the watchman. That's why I wanted you here tonight. I've been suspicious lately — too suspicious to search the way I want. If I had you with me, keeping watch, I might be able to get somewhere." Salisbury, standing by the door, nodded his agreement. Wellington arose and walked over beside him.

"I've got a couple of guns," said the investigator, tapping his pockets grimly. "I'm going to shoot if I see anything that looks funny.

"Now suppose we work it this way. I'm starting downstairs, alone. I'll have the light on — just looking around like I've looked before.

"You come down in a few minutes. I've been up here all evening, and I just might run into something for a starter. That's why I'll go first. You've got a gun?"

"A loaded revolver in the bottom drawer," said Salisbury, pointing to the desk.

"Good," said the investigator. "I'll go ahead. You get your gun and join me." Wellington left the room and advanced stealthily through the darkness. Salisbury drew a key from his pocket and unlocked the desk drawer. He raised a pile of papers, opened a wooden box, and reached in for his revolver.

To his surprise, it was not there. Hubert Salisbury stroked his chin. He was sure that he had put the revolver in that drawer, more than a month ago. He always kept the drawer locked.

Had he taken out the revolver? Or had someone removed it? Salisbury remembered what Wellington had said about persons being in the bank.

This was something that the investigator should know, Salisbury decided. It might be a minor clue nevertheless, it was of value. Salisbury's revolver was a .38 of a special pattern, with his initials on the handle. If they should locate it, he would be able to identify it immediately.

It was time to join Wellington. Leaving the desk, Salisbury started across the floor of the banking room. He felt a slight reluctance about joining Wellington unarmed. Then he realized that the investigator had two guns, and would probably provide him with one.

Nearing the head of the stairs, Salisbury stopped short.

From below came the report of a revolver! Wellington had said that he would fire on suspicion. Had he encountered some one?

Without hesitation, Salisbury shouted and dashed down the stairs. He totally forgot that he was without a weapon.

The room below was lighted. Turning the foot of the stairs, Salisbury nearly stumbled over the body of a man. He looked about excitedly for Wellington. The room was empty — save for the huddled form. In consternation, Salisbury stooped and raised the victim's face. It was Wellington — dead!

The investigator held no weapon; but on the floor, several feet away, lay a revolver.

Hubert Salisbury, like a man in a trance, leaped and seized the gun.

He looked everywhere about the heavy-walled room, and stared through the iron grille work behind which the safe-deposit vaults were located. Had the shot come from there — and had the revolver followed it?

Realizing his dangerous position, Salisbury turned and dashed up the stairs. At the head, he confronted the gleaming torch of the watchman.

"Get help!" exclaimed Salisbury. "Call the police while I wait here! Some one has killed Wellington!" The watchman hastened away, leaving Salisbury peering down the stairway. The watchman had not heard the shot; it was Salisbury's shout that had brought him here.

Cautiously, Salisbury crept down the stairs again and stood there, peering around the corner, over Wellington's body. He turned quickly as he heard men at the top of the stairs. The watchman was coming with a Middletown police sergeant. With a sigh of relief, Salisbury stepped toward Wellington's body, and leaned against the wall as the others arrived.

"I don't know who killed him," he said in a tense voice. "I heard the shot and I rushed down—" With solemn face, the police sergeant plucked the revolver from Salisbury's hand. He glared suspiciously at the young man's pale face. The sergeant examined the weapon.

"This is the gun that killed him?" asked the sergeant.

"Yes," replied Salisbury.

"Where did you get it?"

"I found it here — on the floor. I picked it up" — Salisbury suddenly began to realize the unusualness of his story — "because I thought some one must be here. The shot must have been fired by some one — unless Wellington killed himself—"

"You have a gun of your own?" inquired the sergeant.

"No," said Salisbury weakly, "I was unarmed—"

"Yet you ran down here?"

"Yes."

The sergeant looked at the weapon in his hand. Salisbury looked at the weapon. An astonished gasp came from his lips. It was his missing revolver!

"That — that is my—"

Salisbury stopped as he was blurting out his discovery. Gripped by sudden apprehension, he could go no further. But the sergeant, catching his tone, prompted him.

"What were you saying?" he quizzed.

Denial was useless. Salisbury, though realizing that he was placing himself in a hopeless position, was forced to rely upon the truth.

"That looks like my revolver," he gasped.

"Yes?"

The sergeant's eyes were quizzical as he looked first at the man, then at the weapon.

"H.S.," he said, noting the initials on the handle.

He broke open the revolver, and saw the one fired chamber. He looked about the room.

He could see but one answer to the situation.

"You say you were unarmed," he announced, to Salisbury. "You came down here because you heard a shot. You picked up the gun and started up again. Where did you meet the watchman?"

"Just above the head of the stairs," admitted Salisbury.

"Yes?" queried the sergeant. "You didn't expect to meet him, did you?"

"No."

"Hm-m-m," declared the sergeant. "You might have been on your way out, young fellow. The watchman says you sent him to get us. Lucky he found us right outside the door of the bank — before you had time to get away."

"Get away?" echoed Salisbury.

"Yes." replied the sergeant firmly. "You've told your story, Salisbury. It doesn't go with what I've seen here. Those stairs are the only way in and out of this place. There's the dead man. You're here, with your own gun. And there's no question about it — this gun killed Wellington!"

The sergeant made a motion to two policemen who had followed him. They stepped forward and seized Hubert Salisbury, who sagged limply within their grasp.

"I'm arresting you for murder!" declared the sergeant.

All went black before Hubert Salisbury's eyes. The facts seemed all against him. Innocent though he was, Hubert Salisbury knew that the burden of this crime would be laid upon him!