traced the lines of roads and villages. Each man had his own pet theory. Poirot showed none of his usual loquacity, but sat staring in front of him, with an expression on his face that reminded me of a puzzled child. I talked to Norman, whom I found quite an amusing fellow. On arriving at Dover Poirot's behaviour moved me to intense amusement. The little man, as he went on board the boat, clutched desperately at my arm. The wind was blowing lustily.
"Mon Dieu!" he murmured. "This is terrible!"
"Have courage, Poirot," I cried. "You will succeed. You will find him. I am sure of it."
"Ah, mon ami, you mistake my emotion. It is this villainous sea that troubles me! The mal de mer—it is horrible suffering!"
"Oh!" I said, rather taken aback.
The first throb of the engines was felt, and Poirot groaned and closed his eyes.
"Major Norman has a map of Northern France if you would like to study it?"
Poirot shook his head impatiently.
"But no, but no! Leave me, my friend. See you, to think, the stomach and the brain must be in harmony. Laverguier has a method
