plained. "You will come with me, doctor? And perhaps later Miss Caroline will give us some tea."
"Delighted," said Caroline. "Won't your—er—guest come in also?"
"You are too kind," said Poirot. "But no, my friend reposes himself. Soon you must make his acquaintance."
"Quite an old friend of yours, so somebody told me," said Caroline, making one last valiant effort.
"Did they?" murmured Poirot. "Well, we must start."
Our tramp took us in the direction of Fernly. I had guessed beforehand that it might do so. I was beginning to understand Poirot's methods. Every little irrelevancy had a bearing upon the whole.
"I have a commission for you, my friend," he said at last. "To-night, at my house, I desire to have a little conference. You will attend, will you not?"
"Certainly," I said.
"Good. I need also all those in the house—that is to say: Mrs. Ackroyd, Mademoiselle Flora, Major Blunt, M. Raymond. I want you to be my ambassador. This little reunion is fixed for nine o'clock. You will ask them—yes?"
"With pleasure; but why not ask them yourself?"
"Because they will then put the questions: Why? What for? They will demand what my idea is. And, as you know, my friend, I much dislike to have to explain my little ideas until the time comes."
I smiled a little.
"My friend Hastings, he of whom I told you, used to say of me that I was the human oyster. But he was un-
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