It was just breaking day when, after taking necessary measures to prevent escape, the commissary rang the bell and commenced to question the concierge. The woman was greatly frightened at this early morning invasion, and she trembled as she replied that there were no tenants on the ground floor.

“What! not a tenant?” exclaimed Ganimard.

“No; but on the first floor there are two men named Leroux. They have furnished the apartment on the ground floor for some country relations.”

“A gentleman and lady.”

“Yes.”

“Who came here last night.”

“Perhaps ... but I don’t know ... I was asleep. But I don’t think so, for the key is here. They did not ask for it.”

With that key the commissary opened the door of the ground-floor apartment. It comprised only two rooms and they were empty.

“Impossible!” exclaimed Sholmes. “I saw both of them in this room.”

“I don’t doubt your word,” said the commissary; “but they are not here now.”