Tristan, injured in the foot, takes refuge in a cave where he receives help from Amélia, the daughter of Georges-Marie Dennemont, whom he had once saved from suicide. Recaptured by slave hunters, he is brought back to the plantation where Isaac persuades Charles to limit his punishment to a 30-pound chain to be worn on his feet for a month. Meanwhile, a slave steals a piece of jewelry belonging to Constance Bellevue: Charles orders Isaac to punish her with 30 lashes, but Célestine confesses to the theft, thus forcing her son to administer the whipping himself.

In the midst of a drought, Isaac has other slaves dig a well. Overwhelmed by his role as overseer, he sees in this quest for life-saving water a possible redemption that would allow him to feel better. Meanwhile, Charles tries to resist the pressures of his neighbor, Monsieur Dennemont, but the latter's treachery knows no bounds...

The stores are empty, the slaves are starving. In his father's absence, Henri faces the threat of a revolt. Isaac risks his life to protect the Bellevue family, but his loyalty wavers when he discovers Charles's true nature. Amélia and Tristan decide to run away to be together in the highlands of the island...