"It proves that the thumb-print on the window-pane was not made at the same time as the finger-prints—that it was added separately; and that fact seems to prove that the prints were not made accidentally, but—as you ingeniously suggested just now—were put there for a purpose."
"I don't quite see the drift of all this," said the superintendent, rubbing the back of his head perplexedly; "and you said a while back that the prints on the glass can't be Belfield's because they are identical with the prints on the form. Now that seems to me sheer nonsense, if you will excuse my saying so."
"And yet," replied Thorndyke, "it is the actual fact. Listen: these prints"—here he took up the official sheet—"were taken at Holloway six years ago. These"—pointing to the framed glass—"were made within the present week. The one is, as regards the ridge-pattern, a perfect duplicate of the other. Is that not so?"
"That is so, doctor," agreed the superintendent.
"Very well. Now suppose I were to tell you that within the last twelve months something had happened to Belfield that made an appreciable change in the ridge-pattern on one of his fingers?"
"But is such a thing possible?"
"It is not only possible but it has happened. I will show you."
He brought forth from the drawer the cards on
