Sir Percy is visiting Pierre's parents when he learns that Père Lenègre has been denounced by the concierge Jean Baptiste, who knows Percy often visits them, and that the gendarmes are on their way to arrest him.
While visiting Pierre's parents, Sir Percy learns that Père Lenègre has been denounced by Jean Baptiste, the concierge, who is aware of Percy's frequent visits. Consequently, he discovers that the gendarmes are on their way to arrest him.