Dan Brown's novel turned a thriller plot into a real argument about Christian history, and this film sorts through what set off the fight. It walks through the book's central claims: that Mary Magdalene was Jesus's wife and the mother of a bloodline protected by secret societies, that Leonardo da Vinci hid coded messages about her in works like The Last Supper, and that the Catholic Church suppressed this history for centuries. Scholars and historians weigh in on the Gnostic gospels Brown drew from, explaining what those texts actually say about Mary Magdalene versus what the novel claims for her. The film also traces the backlash, from theologians who called the book heretical fiction to art historians disputing the Da Vinci symbolism point by point. Rather than settling the argument, it lays out where the novel took real scholarship, where it stretched it, and why a work of fiction managed to provoke Vatican statements and academic rebuttals alike.