The profound cogitations of Professor Eccles set up in the mind of Thorndyke a sort of induced psychic current. As he turned from the window and began to occupy himself in sorting his material preparatory to examining it, his thoughts were busy with his late visitor. The professor had been about to say something and had suddenly thought better of it. Now, what could it have been that he was about to say? And why had he not said it? And what was the meaning of that strangely intent look that he had bestowed on Thorndyke, and that rather odd expression that his face had borne? And, finally, what were those “possibilities” at which he had hinted?
These were the questions that Thorndyke asked himself as he carried out, quietly and methodically, the preliminaries to his later investigations; w
