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.

"I don't blame you for adopting a policy of partial concealment," said
the Chief Inspector, spryly. "You are not the first, and you certainly
will not be the last witness from whom the police have to drag the
facts. Now that we have reached more intimate terms, can you help by
describing this stranger?"

Theydon complied at once. He drew just such a general sketch of Forbes
as a skilled observer of men might be expected to formulate after one