“So it did, perhaps, although the inference wouldn’t be very strong.  Go on!”

“There was a fruit-stand on the sideboard, with a plate beside it containing a few nutshells, a piece of apple, a pair of nut-crackers, and, I think, some orange peel.  There was, of course, all the ordinary furniture, but no chair pulled up to the table, except that used by Foggatt himself.  That’s all I noticed, I think.  Stay—­there was an ash-tray on the table, and a partly burned cigar near it—­only one cigar, though.”

“Excellent—­excellent, indeed, as far as memory and simple observation go.  You saw everything plainly, and you remember everything.  Surely now you know how I found out that another man had just left?”

“No, I don’t; unless there were different kinds of ash in the ash-tray.”

“That is a fairly good suggestion, but there were not—­there was only a single ash, corresponding in every way to that on the cigar.  Don’t you remember everything that I did as we went down-stairs?”

“You returned a bottle of oil to the housekeeper’s daughter, I think.”

“I did.  Doesn’t that give you a hint?  Come, you surely have it now?”

“I haven’t.”

“Then I sha’n’t tell you; you don’t deserve it.  Think, and don’t mention the subject again till you have at least one guess to make.  The thing stares you in the face; you see it, you remember it, and yet you won’t see it.  I won’t encourage your slovenliness of thought, my boy, by telling you what you can know for yourself if you like.  Good-by—­I’m off now.  There’s a case in hand I can’t neglect.”

“Don’t you propose to go further into this, then?”

Hewitt shrugged his shoulders.  “I’m not a policeman,” he said.  “The case is in very good hands.  Of course, if anybody comes to me to do it as a matter of business, I’ll take it up.  It’s very interesting, but I can’t neglect my regular work for it.  Naturally, I shall keep my eyes open and my memory in order.  Sometimes these things come into the hands by themselves, as it were; in that case, of course, I am a loyal citizen, and ready to help the law. Au revoir!”

* * * * *

I am a busy man myself, and thought little more of Hewitt’s conundrum for some time; indeed, when I did think, I saw no way to the answer.  A week after the inquest I took a holiday (I had written my nightly leaders regularly every day for the past five years), and saw no more of Hewitt for six weeks.  After my return, with still a few days of leave to run, one evening we together turned into Luzatti’s, off Coventry Street, for dinner.

“I have been here several times lately,” Hewitt said; “they feed you very well.  No, not that table”—­he seized my arm as I turned to an unoccupied corner—­“I fancy it’s draughty.”  He led the way to a longer table where a dark, lithe, and (as well as could be seen) tall young man already sat, and took chairs opposite him.