Domestic service worker Lera is accused of a crime. In a cell in the premises of a Civil Guard barracks, she meets Mihaela and Julia, two prostitutes with whom she shares the story of Santa Vicenta María, founder of the Religious of Mary Immaculate, which she says saved her life.

October, 1936. Concentration camps are being opened throughout the territory by Franco's followers. They use convents, factories, schools, bullrings, monasteries... San Simón stands out for its insular nature. The regime turns the former leper hospital into a place of death, where the prisoners are subjected to repression in a place of astounding beauty. Seven years later, Lamas recalls the story of the men and women who, like himself, suffered repression on this small island off the coast of Galicia.