Act I
Church festivities are taking place to honour of the opening of the Council of Constance. The Jewish goldsmith Éléazar continues to work, invoking the general indignation of the partying Christians. The radical town guardian Ruggiero wants him and his daughter, Rachel, to be put to death, but Cardinal de Brogni intervenes and rescues them. He asks them to forgive the Christians, but Éléazar refuses given all he has suffered at their hands. In a second skirmish, the Jewish father and his daughter are rescued from the crowd by Prince Léopold, who is pretending to be a Jewish artist called Samuel. Rachel is in love with ‘Samuel’ and knows nothing of his true identity.
Act II
Rachel has invited ‘Samuel’ to celebrate Passover at her and her father’s house. Her suspicions are raised when he refuses to eat the piece of unleavened bread that she has given him. Suddenly, Princess Eudoxie, Léopold's wife, turns up to buy a gold chain from Éléazar to give as a present to her husband. ‘Samuel’ confesses to Rachel that he is a Christian. She is distraught, as a relationship between a Christian and a Jew is punishable by death. She is nevertheless willing to elope with him, but before they can leave they are confronted by Éléazar. When he learns of the guest’s true religion, he wants to kill him, but Rachel stops him. She hopes for a conversion and marriage, but for Léopold that is impossible and he is evicted from the house.
Act III
Rachel has followed ‘Samuel’ to the palace. She manages to enter and convince Eudoxie to hire her as a maid. During celebrations of Léopold's victory over the heretical Hussites, Éléazar arrives to deliver the gold chain. When Eudoxie goes to put it on her husband, Rachel and Léopold recognise him as their Passover guest. Rachel accuses the prince of romantic dealings with a Jew: herself. Cardinal de Brogni pronounces a curse on Léopold, Rachel and Éléazar, which Eléazar answers with a curse of his own towards the Christians.
Act IV
Eudoxie begs Rachel to withdraw her allegations. Rachel is still in love with Léopold and so to save him she acquiesces to the princess’s request. Cardinal de Brogni agrees to commute the prince’s sentence and promises to spare Rachel and Éléazar on condition that they convert to Christianity. In response, Éléazar reminds Brogni of the time many years ago when they both lived near Rome. Brogni was not yet a clergyman but a count, and he had executed Éléazar’s sons as heretics before banishing the goldsmith, forcing him to flee to Switzerland. Soon afterwards, bandits looted the count’s home while he was in the city and set it alight. Brogni believed that his wife and baby daughter had been killed in the blaze, but Éléazar tells the now-cardinal that his child was in fact saved by a Jew.
Brogni begs the goldsmith to tell him where his daughter is. Éléazar refuses to reveal the truth – that, on his way to Switzerland, he found the baby near death, abandoned inside the burn-out house, and rescued her, naming her Rachel and raising her as his own daughter. Éléazar promises to take the secret to his grave in order to get revenge on Brogni. Suddenly realising that his hatred of Christians could lead to Rachel’s death as well as his own, Éléazar momentarily changes his mind. But when he hears to cries of the Christian mob calling for his blood, he resolves again to have his revenge.
Act V
Rachel and her father are sentenced to death by being thrown into a cauldron of boiling water. The masses are already looking forward to the spectacle. Éléazar urges Rachel one last time to save herself by being baptised, but, though terrified, she accepts a martyr's death alongside her father. When the young woman is thrown into the cauldron, Éléazar reveals his secret to Brogni. The cardinal falls to his knees as the crowd celebrate their vengeance over the Jews.