After receiving news from France of his father’s sudden death, Damien Louvel returns to his homeland from America, where he has spent more than ten years. At home he begins sorting through his father’s manuscripts and learns that the elder Louvel had devoted many years to researching a mysterious relic—the Jordan Stone—whose two-thousand-year history involved the first Christians, the Templars, the Freemasons, Leonardo da Vinci, and even Napoleon. It soon becomes clear that these very studies cost the historian his life, yet Damien decides to continue them.