'Yes. Most probably. Broke it, and then remembered that anyone at the windows of the boarding Houses might see him, so left his job half done, and shifted his point of action. I think so. Yes.'
He moved on again till he came to the other window. Then he gave vent to an excited exclamation, and picked up a piece of caked mud from the sill as carefully as if it were some fragile treasure.
'Now, see this,' he said. 'This was wet when the robbery was done. The man brought it in with him. On his boot. Left it on the sill as he climbed in. Got out in a hurry, startled by something—you can see he was startled and left in a hurry from the different values of the cups he took—and as he was going, put his hand on this. Left a clear impression. Good as plaster of Paris very nearly.'
Mr Thompson looked at the piece of mud, and there, sure enough, was the distinct imprint of the palm of a hand. He could see the larger of the lines quite clearly, and under a magnifying-glass there was no doubt that more could be revealed.
He drew in a long breath of satisfaction and excitement.
'Yes,' said the detective. 'That piece of mud couldn't prove anything by itself, but bring it up at the end of a long string of evidence, and if it fits your man, it convicts him as much as a snap-shot photograph would. Morning, sir. I must be going.' And he retired, carrying the piece of mud in his hand, leaving Mr Thompson in the full grip of the detective-fever, hunting with might and main for more clues.
After some time, however, he was reluctantly compelled to give up the search, for the bell rang for dinner, and he always lunched, as did many of the masters, in the Great Hall. During the course of the meal he exercised his brains without pause in the effort to discover a fitting suspect. Did he know of any victim of kleptomania in the School? No, he was sorry to say he did not. Was anybody in urgent need of money? He could not say. Very probably yes, but he had no means of knowing.
After lunch he went back to the Common Room. There was a letter lying on the table. He picked it up. It was addressed to 'J. Thomson, St Austin's.' Now Mr Thompson's Christian name was John. He did not notice the omission of the p until he had opened the envelope and caught a glimpse of the contents. The letter was so short that only a glimpse was needed, and it was not till he had read the whole that he realised that it was somebody else's letter that he had opened.
This was the letter:
'Dear Jim—Frantic haste. Can you let me have that two pounds directly you come back? Beg, borrow, or steal it. I simply must have it.—Yours ever,