Page:Knaves of Diamonds.pdf/173

 say that none of the fiction that I have so far heard has offered even a reasonable explanation of the disappearance of that diamond, given the conditions which you have just stated, and, as far as I can see, I admit that I couldn't give the remotest guess at the solution of the mystery."

"That's exactly what I said to myself after I had been worrying day and night for more than a week over it," said the inspector. "And then," he went on, suddenly getting up from his seat and beginning to walk up and down the room with quick, irregular strides, "all of a sudden, in the middle of a very much smaller puzzle, just one of the common I.D.B. cases we have almost every week, the whole of the work that I was engaged upon vanished from my mind, leaving it for the moment a perfect blank. Then like a lightning flash out of a black cloud, there came a momentary ray of light which showed me