Poirot's self-possession was marvellous. He did not turn a hair. But I saw his eyes searching in the shadows.

"My friend? He is here?"

"Yes, you are both in the trap—the trap of the Big Four."

He laughed.

"A trap?" queried Poirot.

"Say, haven't you tumbled to it yet?"

"I comprehend that there is a trap—yes," said Poirot gently. "But you are in error, monsieur. It is you who are in it—not I and my friend."

"What?" Ryland raised the big automatic, but I saw his gaze falter.

"If you fire, you commit murder watched by ten pairs of eyes, and you will be hanged for it. This place is surrounded—has been for the last hour—by Scotland Yard men. It is checkmate, Mr. Abe Ryland."

He uttered a curious whistle, and as though by magic, the place was alive with men. They seized Ryland and the valet and disarmed them. After speaking a few words to the officer in charge, Poirot took me by the arm, and led me away.