They were silent.
Suddenly the Duke said, "Somebody's coming." Guerchard started, and said: "No, I don't hear any one." Then there came distinctly the sound of a footstep and a knock at the door.
"You've got keener ears than I," said Guerchard grudgingly.

"In all this business you've shown the qualities of a very promising detective." He rose, went to the door, and unlocked it.
Bonavent came in: "I've brought you the handcuffs, sir," he said, holding them out.

"Shall I stay with you ?" "No," said Guerchard.

"You've two men at the back door, and two at the front, and a man in every room on the ground-floor ?" "Yes, and I've got three men on every other floor," said Bonavent, in a tone of satisfaction.
"And the house next door ?" said Guerchard.
"There are a dozen men in it," said Bonavent.

"No communication between the two houses is possible any longer." Guerchard watched the Duke's face with intent eyes.