Splendeurs et misères des courtisanes, the sequel to Lost Illusions, is a vast novel in four parts blending high society and the underworld. Saved from suicide by the false Spanish priest Carlos Herrera — in reality the convict Vautrin — Lucien de Rubempré returns to Paris under the protection of this strange mentor, who finances his reintroduction into high society and nurses immense ambitions for him: a great marriage to Clotilde de Grandlieu, fortune, power. Lucien secretly loves a former courtesan of dazzling beauty, Esther Gobseck, called "la Torpille," whom Vautrin hides and uses as an instrument. When the immensely rich Baron de Nucingen falls madly in love with Esther, Vautrin seizes the occasion: he compels the young woman to sell herself to the banker to extort a fortune destined to fund Lucien's ascent. But Esther, torn between her love for Lucien and the degradation imposed on her, poisons herself in despair. Her death triggers an investigation: Lucien, suspected, is arrested and imprisoned at the Conciergerie. Broken by interrogation, he confesses, compromises Vautrin, then hangs himself in his cell. Vautrin, cornered and deprived of his creature, then accomplishes a stunning reversal: by an audacious bargain with the police, this master of crime reforms and becomes chief of the Sûreté. Balzac interweaves the splendors of the salons with the miseries of the prisons, painting the criminal underside of brilliant society. The novel deepens the demonic figure of Vautrin, denounces corruption and justice, and brings the destiny of Lucien to its tragic term. It is one of the most powerful frescoes of the cycle, where ambition, love, and crime meet in catastrophe.