Amid the French Wars of Religion, Jean de Sponde (1557-1595), a law student in Geneva, completes an alchemical experiment in which he believes he has changed silver into gold--one substance into another-leading him to think the Roman Catholic Eucharist might be true. Berated by the patriarch of Calvinism, Théodore de Bèze, he flees home to Navarre. There, Protestant King Henri recruits him for his legal expertise and trains him as a knight. He fights in the Battle of Coutras. In Rome, he befriends Bishop du Perron. He writes glorious poems to his fiancée, Anne Legrand, whom he later marries. The king sends him to Paris to spy, but he is captured and imprisoned, eventually saved by Du Perron. Henri, in direct line of succession to the throne of France, cannot accede as a Protestant. Jean, whose Protestant (Huguenot) faith is shaky, persuades him to convert. The king does so and becomes Henri IV of France. Jean agonizes over the choice, but also converts a month later. The king suspects him of conniving for personal advantage and exiles him. Jean dies at age 38 just before King Henri IV stops the wars with the Edit de Nantes, allowing France to become a peaceful and prosperous nation once again..