M. Formery shook his head sadly.
"I was wondering," said the Duke, "about M. Guerchard's theory that the burglars were let in the front door of this house by an accomplice. Why, when they had this beautiful large opening, did they want a front door, too?"
"I did not know that that was Guerchard's theory?" said M. Formery, a trifle contemptuously. "Of course they had no need to use the front door."
"Perhaps they had no need to use the front door," said Guerchard; "but, after all, the front door was unbolted, and they did not draw the bolts to put us off the scent. Their false scent was already prepared"—he waved his hand towards the window—"moreover, you must bear in mind that that opening might not have been made when they entered the house. Suppose that, while they were on the other side of the wall, a brick had fallen on to the hearth, and alarmed the concierge. We don't know how skilful they are; they might not have cared to risk it. I'm inclined to think, on the whole, that they did come in through the front door."
M. Formery sniffed contemptuously.
"Perhaps you're right," said the Duke. "But the accomplice?"
"I think we shall know more about the accomplice
