"How did I know?" repeated the young man. "Oh, a little bird told me."
When Mike had left the office Paul took a chair before the fire and lighted a cigar. For half an hour he sat silently thinking.
He came to the conclusion that Mr. Wheatcroft was right in his suspicion. Whittier, Wheatcroft & Co. had lost important contracts because of underbidding, due to knowledge surreptitiously obtained. He believed that some one had got into the store on Sunday while Mike was taking a walk, and that this somebody had somehow opened the safe. There never was any money in that private safe; it was intended to contain only important papers. It did contain the letter-book of the firm's bids, and this is what was wanted by the man who had got into the office, and who had let himself in by the window, leaving it unfastened behind him. How this man had got in, and why he did not get out by the way he entered, how he came to be able to open the private safe, the combination of which was known only to the two partners—these were questions for which Paul Whittier had no answer.
What grieved him when he had come to the conclusion was that the thief—for such the house-breaker was in reality—was probably one of the men in the employ of the firm. It seemed to him almost certain that the man who had broken in knew all the ins and outs of the office. And how could this knowledge have been obtained except by an employee? Paul was well acquainted with the clerks in the outer office. There were five of them, including the old book-keeper, and although none of them had been with the firm as long as the Major, no one of them had been there less than ten years. Paul did not know which one to suspect. There was, in fact, no reason to suspect any particular clerk. And yet that one of the five men in the main office on the other side of the glass partition within twenty feet of him—that one of those was the guilty man Paul did not doubt.
And therefore it seemed to him not so important to prevent the thing from happening again as it was to catch the man who had done it. The thief once caught, it would be easy thereafter for the firm to take unusual precautions. But the first thing to do was to catch the thief. He had come and gone, and left no trail. But he must have visited the office at least three times in the past few weeks, since the firm had lost three important contracts. Probably he had been there oftener than three times. Certainly he would come again. Sooner or later he would come once too often. All that needed to be done was to set a trap for him.
While Paul was sitting quietly in the private office, smoking a cigar with all his mental faculties at their highest tension, the clock in the corner suddenly struck three.
Paul swiftly swung around in his chair and looked at it. An old eight-day clock it was, which not only told the time of the day, but pretended, also, to supply miscellaneous astronomical information. It stood by itself in the corner.
For a moment after it struck Paul stared at it with a fixed gaze, as though he did not see what he was looking at. Then a light came into his eyes and a smile flitted across his lips.
He turned around slowly and measured with his eye the proportions of the room, the distance between the desks and the safe and the clock. He glanced up at the sloping glass roof above him. Then he smiled again, and again sat silent for a minute. He rose to his feet and stood with his back to the fire. Almost in front of him was the clock in the corner.
He took out his watch and compared its time with that of the clock. Apparently he found that the clock was too fast, for he walked over to it and turned the minute-hand back. It seemed that this was a more difficult feat than he supposed or that he went about it carelessly, for the minute-hand broke off short in his fingers. A spasmodic movement of his, as the thin metal snapped, pulled the chain off its cylinder, and the weight fell with a crash.