For more than seventy years, the French village of Rennes-le-Château has drawn treasure hunters chasing a story about a local priest, Bérenger Saunière, who supposedly found a hidden fortune, or a hidden secret about the bloodline of Christ, inside his parish church in the 1890s. The tale metastasized through the twentieth century into forged parchments, a supposed secret society called the Priory of Sion, and eventually into the plot of Dan Brown's novel and film The Da Vinci Code. This film sends historians and researchers back to the village, its church, and the archives to trace the myth to its source: a mid-century con artist named Pierre Plantard, who fabricated the documents that later writers treated as evidence. Interviews and on-location footage walk through how a small-town fraud became one of the most durable conspiracy stories in modern publishing. What Saunière actually did with his money turns out to be a far less mystical story than the legend built on top of it.