“‘How, Cay, how?’ he said eagerly.

“‘Well, I haven’t really thought it out,’ I protested.  ’It was just an idea.’

“He began to think it out for himself.

“’I might pretend to be a manager, come down to see her—­but I suppose she knows them all.  What about an interviewer?’

“‘It’s going to be difficult,’ I said thoughtfully.  ’You’ve got rather a characteristic face, you know.  And your beard—­’

“‘I’d shave it off,’ he snapped.

“‘My dear Mark!’

“He looked away, and mumbled, ’I’ve been thinking of taking it off, anyhow.  And besides, if I’m going to do the thing, I’m going to do it properly.’

“‘Yes, you always were an artist,’ I said, looking at him admiringly.

“He purred.  To be called an artist was what he longed for most.  Now I knew that I had him.

“‘All the same,’ I went on, ’even without your beard and moustache you might be recognizable.  Unless, of course—­’ I broke off.

“‘Unless what?’

“‘You pretend to be Robert.’  I began to laugh to myself again.  ‘By Jove!’ I said, ’that’s not a bad idea.  Pretend to be Robert, the wastrel brother, and make yourself objectionable to Miss Norris.  Borrow money from her, and that sort of thing.’

“He looked at me, with his bright little eyes, nodding eagerly.

“‘Robert,’ he said.  ‘Yes.  How shall we work it?’

“There was really a Robert, Mr. Gillingham, as I have no doubt you and the Inspector both discovered.  And he was a wastrel and he went to Australia.  But he never came to the Red House on Tuesday afternoon.  He couldn’t have, because he died (unlamented) three years ago.  But there was nobody who knew this, save Mark and myself, for Mark was the only one of the family left, his sister having died last year.  Though I doubt, anyhow, if she knew whether Robert was alive or dead.  He was not talked about.

“For the next two days Mark and I worked out our plans.  You understand by now that our aims were not identical.  Mark’s endeavour was that his deception should last for, say, a couple of hours; mine that it should go to the grave with him.  He had only to deceive Miss Norris and the other guests; I had to deceive the world.  When he was dressed up as Robert, I was going to kill him.  Robert would then be dead, Mark (of course) missing.  What could anybody think but that Mark had killed Robert?  But you see how important it was for Mark to enter fully into his latest (and last) impersonation.  Half-measures would be fatal.

“You will say that it was impossible so do the thing thoroughly enough.  I answer again that you never knew Mark.  He was being what he wished most to be—­an artist.  No Othello ever blacked himself all over with such enthusiasm as did Mark.  His beard was going anyhow—­possible a chance remark of Miss Norbury’s helped here.  She did not like beards.  But it was important for me that the dead man’s hands should not be the hands of a manicured gentleman.  Five minutes playing upon the vanity of the artist settled his hands.  He let the nails grow and then cut them raggedly.  ‘Miss Norris would notice your hands at once,’ I had said.  ‘Besides, as an artist—­’