The following facts were at once established by an examination of the prison records: Eight weeks before a man named Baudru Désiré had slept at the Dépôt . He was released the next day, and left the Dépôt at two o’clock in the afternoon. On the same day at two o’clock, having been examined for the last time, Arsène Lupin left the Dépôt in a prison-van.

Had the guards made a mistake? Had they been deceived by the resemblance and carelessly substituted this man for their prisoner?

Another question suggested itself: Had the substitution been arranged in advance? In that event Baudru must have been an accomplice and must have caused his own arrest for the express purpose of taking Lupin’s place. But then, by what miracle had such a plan, based on a series of improbable chances, been carried to success?