Theydon’s feelings changed rapidly while Winter was delivering this very convincing analysis of a few simple facts.  He had passed at a bound from the detected schoolboy stage to that of a man forcing his way through a thicket who finds himself on the very lip of a precipice.

He remembered hazily that Bates had said something at Waterloo with regard to the manner in which the detectives, especially Furneaux, had questioned him.  But it was too late to apply the warning thus conveyed.  If he faltered now he was forever discredited.  These men would read his perplexed face as if it were a printed page.  In his distress be was prepared to hear Winter or that little satyr, Furneaux, say mockingly: 

“Why are you trying to screen James Creighton Forbes?  What is he to you?  What matter his fame or social rank?  We are here to see that justice is done.  Out with the truth, let who may suffer.”

But neither of the pair said anything of the sort.  Furneaux only interjected a sarcastic comment.

“You will observe, Mr. Theydon, that even in a minor instance of deductive reasoning, such as this, the man who smells rather than the man who smokes tobacco solves the problem promptly.”

Theydon threw out his hands in token of surrender.  He thought he saw a means of escape, and took it unhesitatingly.

“I’m vanquished,” he said.  “You force me to admit that I do know a little, a very little, more than I have confessed hitherto about the man who visited Mrs. Lester’s flat last night.  I have said nothing about the matter thus far because I didn’t want to be convicted of a piece of idle curiosity worthy of a gossip-loving housemaid.  I noticed the man I have described staring at the name tablet of the street as my cab turned the corner.  I did not know him.  I had never seen him before last night, but he was of such distinguished appearance and his face was of so rare a type that I was interested and wished to ascertain, if possible, on whom he meant calling if, as it seemed, he was searching for an address in these flats.  Therefore, I did look out, and saw him enter the doorway beneath.  In due course I heard him arrive at Mrs. Lester’s door—­ that is, I assume it was he.  Five minutes later Bates and I heard him depart.  To make sure, I looked out a second time.  If you ask me why I behaved in that way I cannot tell you.  I have occupied this flat during the past five months, and I have never previously, within my recollection, lifted a window and gazed out to watch anybody’s comings and goings.  The thing is inexplicable.  All I can say is that it just happened.”

“Would you recognize him if you saw him again?”

“Yes.”

Theydon gave the assurance readily.  It was beyond credence that either detective should put the one question to which he was now firmly resolved to give a misleading answer, and in this belief he was justified, since not even Furneaux’s uncanny intelligence could suggest the fantastic notion that the man who walked through the rain the previous night and the man with whom Theydon had dined that evening were one and the same person.