The Duke followed him, and in the hall said: “I will continue to watch you unravel the threads of this mystery, if I may, M. Guerchard.”
Good Republican as Guerchard was, he could not help feeling flattered by the interest of a Duke; and the excellent lunch he had eaten disposed him to feel the honour even more deeply.
“I shall be charmed,” he said. “To tell the truth, I find the company of your Grace really quite stimulating.”
“It must be because I find it all so extremely interesting,” said the Duke.
They went up to the drawing-room and found the red-faced young policeman seated on a chair by the door eating a lunch, which had been sent up to him from the millionaire’s kitchen, with a very hearty appetite.
They went into the drawing-room. Guerchard shut the door and turned the key: “Now,” he said, “I think that M. Formery will give me half an hour to myself. His cigar ought to last him at least half an hour. In that time I shall know what the burglars really did with their plunder—at least I shall know for certain how they got it out of the house.”
“Please explain,” said the Duke. “I thought we knew how they got it out of the house.” And he waved his hand towards the window.
“Oh, that!—that’s childish,” said Guerchard contemptuously. “Those are traces for an examining magistrate. The ladder, the table on the window-sill, they lead nowhere. The only people who came up that ladder were the two men who brought it from the scaffolding. You can see their footsteps. Nobody went down it at all. It was mere waste of time to bother with those traces.”
“But the footprint under the book?” said the Duke.
“Oh, that,” said Guerchard. “One of the burglars sat on the couch there, rubbed plaster on the sole of his boot, and set his foot down on the carpet. Then he dusted the rest of the plaster off his boot and put the book on the top of the footprint.”