Coincidence puts him back on the track. One day curiosity impels him to observe his neighbors through a hole in the wall. He glimpses a family — father, mother, and two daughters — living in unspeakable squalor. Soon after he witnesses the entrance of a philanthropist, M. Leblanc, and his daughter. To his immense surprise, the daughter is Cosette. His jubilation is replaced by consternation when he discovers that his neighbors are planning to draw M. Leblanc into a trap the same evening. Marius contacts the police and on the instructions of Inspector Javert returns to his room.
When Leblanc comes back, Marius' neighbor identifies himself as Thénardier, ties up his victim, and demands an exorbitant ransom. The plot fails with the timely arrival of the inspector. In the confusion of the arrest, Leblanc escapes.
Once again, the young girl has vanished. But Thénardier's daughter, who is selflessly in love with Marius, manages to find his sweetheart for him.
After worshiping Cosette from afar, Marius summons the courage to declare his love. Cosette reciprocates. For a whole month the couple lives a chaste and secret idyll, secret because Cosette intuitively guesses Valjean's hostility to the man who is usurping his place.
Marius' happiness is unwittingly shattered by Valjean, who, disturbed by a secret warning and the growing popular unrest in Paris, has decided to take Cosette to England. As a first step he moves to a hideaway prepared for this kind of emergency.
