By accident, Cosette is prevented from communicating with Marius.

Knowing that Marius cares only for Cosette, Eponine despairs and writes an anonymous note summoning him to join his friends fighting on the barricades of the worker-student insurrection of 1832. She hopes he will die there; but she wants to die first, by his side. In despair at not finding Cosette at home, Marius seeks death on the barricades. There, a sudden political illumination makes his commitment to his friends’ republican cause authentic. Eponine, disguised as a young worker, saves Marius by throwing herself in front of a bullet aimed at him.

Meanwhile, Valjean has discovered the imprint of Cosette’s desperate note to Marius on her blotter. Her adoptive father is taking her away; she does not know where. Valjean hates Marius for threatening to deprive him of the only person he has ever loved. He struggles to overcome his possessiveness, and despite his rage, he goes to the barricades to protect Marius. Behind the barricade, Javert has been unmasked as a police spy. Valjean asks permission to execute him, but secretly sets him free. As the barricade falls to the government troops, Marius collapses, wounded and unconscious. Valjean escapes through the sewers, carrying the young man through the foul muck on his shoulders for four miles.

At the locked exit by the Seine, Valjean meets Thénardier, who has hidden there from Javert. Thénardier does not recognize Valjean. He thinks Valjean has killed Marius for his money, and demands all Valjean’s cash in exchange for opening the gate with his skeleton key so that Valjean can escape. He hopes to divert the waiting Javert by offering him a substitute fugitive. Javert does indeed arrest Valjean, but feels morally obligated to release him, because he owes the convict his life. Then, torn by an insoluble conflict between religious and legal duty, Javert drowns himself. Marius’s repentant grandfather nurses Marius back to health and marries him to Cosette. Valjean has given her all his fortune. The novel reaches its moral climax on the wedding night. Should Valjean confess that he is an escaped convict, and renounce all contact with Cosette to spare the young couple the shame of his possible denunciation and arrest? “He had reached the last crossing of good and evil.... two roads opened before him; the one tempting, the other terrible. Which should he take? The one which terrified him was advised by the mysterious indicating finger which we all perceive whenever we fix our eyes upon the shadow.... We are never done with conscience.... It is bottomless, being God” (pp. 769—770). Human love alone cannot bring us closer to God. Sacrifice is required.

The next day, Valjean secretly confesses to Marius that he is an escaped convict, and not Cosette’s father. Marius, believing that Valjean’s fortune was stolen, does not touch it. Thinking that Valjean killed Javert at the barricade, Marius only reluctantly allows him to see Cosette in the anteroom to his grandfather’s house.