In 1730 the French authorities seized nineteen-year-old Marie Durand (1711–76), shaved her head, and imprisoned her in the dreadful Tour de Constance. Punished for her Protestant faith, she could have walked out of her dungeon if she had converted to Catholicism. Refusing to abandon her family’s faith, she was held for thirty-eight years, until her prison was closed by the authorities in 1768. While imprisoned Marie wrote letters to pastors and churches pleading for their help, and letters of motherly love to her orphaned niece in Geneva. She even wrote to the Queen of France. This first English translation of Marie Durand’s forty-eight surviving letters is joined to a biography and analysis of what she said about freedom of conscience, suffering, charity, and how Christians ought to relate to a persecuting government. Her thoughts, written from a place of deep suffering, are just as relevant today as they were nearly three centuries ago.