Sion Grand Master Jacques Saunie

Louvre curator and Priory of Sion Grand Master Jacques Saunière is fatally shot one night at the museum by an albino Catholic monk named Silas, who is working on behalf of someone he knows only as the Teacher, who wishes to discover the location of the "keystone", an item crucial to the search for the Holy Grail. After Saunière's body is discovered in the pose of the Vitruvian Man, the police summon Harvard Professor Robert Langdon, who is in town on business. Police Captain Bezu Fache tells him that he was summoned to help the police decode the cryptic message Saunière left during the final minutes of his life. The message includes a Fibonacci sequence out of order. Langdon explains to Fache that Saunière was a leading authority on the subject of goddess artwork and that the pentacle Saunière drew in his own blood represents an allusion to the goddess and not "devil worship", as Fache says.

A police cryptographer, Sophie Neveu, secretly explains to Langdon that she is Saunière's estranged granddaughter, and that Fache thinks Langdon is the murderer, because her grandfather's message said "PS Find Robert Langdon", which she says Fache had erased prior to Langdon's arrival. Neveu is troubled by memories of her grandfather's involvement in a secret pagan group. However, she understands that her grandfather intended Langdon to

Arriving home unexpectedly from university, Neveu clandestinely witnesses a spring fertility rite conducted in the secret basement of her grandfather's country estate. From her hiding place, she is shocked to see her grandfather having sex with a woman at the center of a ritual attended by men and women who are wearing masks and chanting praise to the goddess. She flees the house and breaks off all contact with Saunière. Langdon explains that what she witnessed was an ancient ceremony known as Hieros gamos or "sacred