"Yes."
"At last!" cried the prince, joyfully.
The others looked at him in surprise.
"Why, of course," he said, "that's a clue!"
"Do you think so?"
"Evidently. The murder of Chapman can only have been committed in one of the rooms on that passage. Mr. Kesselbach's murderer took the secretary there, to an accomplice, killed him there, changed his clothes there; and, once the murderer had got away, the accomplice placed the corpse in the passage. But which accomplice? The manner of Major Parbury's disappearance goes to show that he knows something of the business. Quick, telephone the good news to M. Lenormand or Gourel. The Prefecture must be informed as soon as possible. The people there and I are marching hand in hand."
He gave them a few more injunctions, concerning their double rôle as police-inspectors in the service of Prince Sernine, and dismissed them.
Two visitors remained in the waiting-room. He called one of them in:
"A thousand pardons, Doctor," he said. "I am quite at your orders now. How is Pierre Leduc?"
"He's dead."