The Duke inquired if any trace of the burglars, after they had left with their booty, had yet been found. M. Formery told him that, so far, the detectives had failed to find a single trace. Guerchard said that he had three men at work on the search, and that he was hopeful of getting some news before long.
"The layman is impatient in these matters," said M. Formery, with an indulgent smile. "But we have learnt to be patient, after long experience."
He proceeded to discuss with Guerchard the new theories with which the discovery of the afternoon had filled his mind. None of them struck the Duke as being of great value, and he listened to them with a somewhat absent-minded air. The coming examination of Sonia weighed heavily on his spirit. Guerchard answered only in monosyllables to the questions and suggestions thrown out by M. Formery. It seemed to the Duke that he paid very little attention to him, that his mind was still working hard on the solution of the mystery, seeking the missing facts which would bring him to the bottom of it. In the middle of one of M. Formery's more elaborate dissertations the telephone bell rang.
Guerchard rose hastily and went to it. They
