Part 76

Thus was fixed definitely the moment at which the robbery occurred. It was shown that the policeman on the beat had been four blocks away. It was perfectly possible that no one heard the explosion, because the bank was situated in a part of the city wholly given over to business and deserted at night.

The burglars had entered the building through a window of the cashier's private office, in the full glare of an electric light. The window sash here had been found unfastened and the protecting steel bars, outside from top to bottom, seemed to have been dragged from their sockets in the solid granite. The granite crumbled away, as if it had been chalk.

Only one possible clew was found. This was a white linen handkerchief, picked up in front of the blown safe. It must have been dropped there at the time of the burglary, because Dunston distinctly recalled it was not there before he left the bank. He would have noticed it while the janitor was sweeping.

This handkerchief was the property of Cashier West. The cashier did not deny it, but could offer no explanation of how it came there. Miss Clarke and Dunston both said that they had seen him leave the bank with a handkerchief in his hand.

II.

President Fraser reached the bank at ten o'clock and was informed of the robbery. He retired to his office, and there he sat, apparently stunned into inactivity by the blow, his head bowed on his arms. Miss Clarke, at her typewriter, frequently glanced at the aged figure with an expression of pity on her face. Her eyes seemed weary, too. Outside, through the closed door, they could hear the detectives.

From time to time employees of the bank and detectives entered the office to ask questions. The banker answered as if dazed; then the board of directors met and voted to personally make good the loss sustained. There was no uneasiness among depositors, because they knew the resources of the bank were practically unlimited.

Cashier West was not arrested. The directors wouldn't listen to such a thing; he had been cashier for eighteen years, and they trusted him implicitly. Yet he could offer no possible explanation of how his handkerchief had come there. He asserted stoutly that he had not been in the bank from the moment Miss Clarke and Dunston saw him leave it.

After investigation the police placed the burglary to the credit of certain expert cracksmen, identity unknown. A general alarm, which meant a rounding up of all suspicious persons, was sent out, and this drag-net was expected to bring important facts to light. Detective Mallory said so, and the bank officials placed great reliance on his word.

Thus the situation at the luncheon hour. Then Miss Clarke, who, wholly unnoticed, had been waiting all morning at her typewriter, arose and went over to Fraser.

"If you don't need me now," she said, "I'll run out to luncheon."

"Certainly, certainly," he responded, with a slight start. He had apparently forgotten her existence.

She stood silently looking at him for a moment.

"I'm awfully sorry," she said, at last, and her lips trembled slightly.

"Thanks," said the banker, and he smiled faintly. "It's a shock, the worst I ever had."

Miss Clarke passed out with quiet tread, pausing for a moment in the outer office to stare curiously at the shattered steel safe. The banker arose with sudden determination and called to West, who entered immediately.

"I know a man who can throw some light on this thing," said Fraser, positively. "I think I'll ask him to come over and take a look. It might aid the police, anyway. You may know him? Professor Van Dusen."

"Never heard of him," said West, tersely, "but I'll welcome anybody who can solve it. My position is uncomfortable."

President Fraser called Professor Van Dusen--The Thinking Machine--and talked for a moment through the 'phone. Then he turned back to West.

"He'll come," he said, with an air of relief. "I was able to do him a favor once by putting an invention on the market."

Within an hour The Thinking Machine, accompanied by Hutchinson Hatch, reporter, appeared. President Fraser knew the scientist well, but on West the strange figure made a startling, almost uncanny, impression. Every known fact was placed before The Thinking Machine. He listened without comment, then arose and wandered aimlessly about the offices. The employees were amused by his manner; Hatch was a silent looker-on.

"Where was the handkerchief found?" demanded The Thinking Machine, at last.

"Here," replied West, and he indicated the exact spot.

"Any draught through the office--ever?"

"None. We have a patent ventilating system which prevents that."

The Thinking Machine squinted for several minutes at the window which had been unfastened--the window in the cashier's private room--with the steel bars guarding it, now torn out of their sockets, and at the chalklike softness of the granite about the sockets. After awhile he turned to the president and cashier.

"Where is the handkerchief?"

"In my desk," Fraser replied. "The police thought it of no consequence, save, perhaps--perhaps----," and he looked at West.