"But the servants' staircase?"
"The servants' staircase leads to the courtyard and there's only one outlet, the front door: I have ten men watching it."
"But he did not come in by the front door.... He won't go out that way either...."
"Which way, then?" jeered Ganimard. "Through the air?"
He drew back a curtain. A long passage was revealed, leading to the kitchen. Ganimard ran down it and found that the door of the servants' staircase was double-locked.
Opening the window, he called to one of the detectives:
"Seen any one?"
"No, sir."
"Then," he exclaimed, "they are in the flat!... They are hiding in one of the rooms!... It is physically impossible for them to have escaped.... Ah, Lupin, my lad, you did me once, but I'm having my revenge this time!..."