“It will be the best plan,” agreed the little Belgian. “This evening I shall want mademoiselle—I beg her pardon, madame—to attend my little reunion. Nine o’clock at my house. It is most necessary that she should be there.”

Caroline nodded, and went with Ursula out of the room. The door shut behind them. Poirot dropped down into a chair again.

“So far, so good,” he said. “Things are straightening themselves out.”

“They’re getting to look blacker and blacker against Ralph Paton,” I observed gloomily.

Poirot nodded.

“Yes, that is so. But it was to be expected, was it not?”

I looked at him, slightly puzzled by the remark. He was leaning back in the chair, his eyes half closed, the tips of his fingers just touching each other. Suddenly he sighed and shook his head.

“What is it?” I asked.

“It is that there are moments when a great longing for my friend Hastings comes over me. That is the friend of whom I spoke to you—the one who resides now in the Argentine. Always, when I have had a big case, he has been by my side. And he has helped me—yes, often he has helped me. For he had a knack, that one, of stumbling over the truth unawares—without noticing it himself, bien entendu. At times he has said something particularly foolish, and behold that foolish remark has revealed the truth to me! And then, too, it was his practice to keep a written record of the cases that proved interesting.”

I gave a slight embarrassed cough.