which I might have missed.

"'Wonderful,' I said to myself again. 'Nobody could possibly guess.'

"I peered into the hall. It was empty. We hurried across to the library;
he got into the passage and made off. I went back to the bedroom,
collected all his discarded clothes, did them up in a bundle and
returned with them to the passage. Then I sat down in the hall and
waited.

"You heard the evidence of Stevens, the maid. As soon as she was on her
way to the Temple in search of Mark, I stepped into the office. My hand
was in my side-pocket, and in my hand was the revolver.

"He began at once in his character of Robert--some rigmarole about
working his passage over from Australia; a little private performance
for my edification. Then in his natural voice, gloating over his
well-planned retaliation on Miss Norris, he burst out, 'It's my turn
now. You wait.' It was this which Elsie heard. She had no business to be
there and she might have ruined everything, but as it turned out it was
the luckiest thing which could have happened. For it was the one piece
of evidence which I wanted; evidence, other than my own, that Mark and
Robert were in the room together.

"I said nothing. I was not going to take the risk of being heard to
speak in that room. I just smiled at the poor little fool, and took
out my revolver, and shot him. Then I went back into the library and
waited--just as I said in my evidence.

"Can you imagine, Mr. Gillingham, the shock which your sudden appearance
gave me? Can you imagine the feelings of a 'murderer' who has (as he
thinks) planned for every possibility, and is then confronted suddenly
with an utterly new problem? What difference would your coming make? I
didn't know. Perhaps none; perhaps all. And I had forgotten to open the
window!

"I don't know whether you will think my plan for killing Mark a clever
one. Perhaps not. But if I do deserve any praise in the matter, I think
I deserve it for the way I pulled myself together in the face of the
unexpected catastrophe of your arrival. Yes, I got a window open, Mr.
Gillingham, under your very nose; the right window too, you were kind
enough to say. And the keys--yes, that was clever of you, but I think I
was cleverer. I deceived you over the keys, Mr. Gillingham, as I
learnt when I took the liberty of listening to a conversation on the
bowling-green between you and your friend Beverley. Where was I? Ah, you
must have a look for that secret passage,