Jacques Saunière, the Louvre's curator, is pursued through the Grand Gallery by an albino Catholic monk named Silas, who demands the location of the Priory's "keystone" to find and destroy the Holy Grail. Saunière gives him a false lead and is murdered. When the police arrive, they find his body posed like Da Vinci's Vitruvian Man. The police captain, Bezu Fache, sends his lieutenant, Jérôme Collet, to summon American symbologist Robert Langdon, in the midst of signing autographs after one of his public talks, to examine Saunière's body.
At CERN, Father Silvano and Dr. Vittoria Vetra create three canisters of antimatter. Silvano is murdered, and one of the canisters is stolen. The Roman Catholic Church mourn the sudden death of Pope Pius XVI, and prepare for the papal conclave to elect his successor in Vatican City. Father Patrick McKenna, the Camerlengo of the Holy Roman Church, takes control of the Vatican. Four of the “preferiti”, the favoured candidates to be Pope, are kidnapped by a man claiming to represent the Illuminati. He sends the Vatican a warning, claiming he will murder each of the cardinals from 8pm to midnight, where the stolen antimatter will explode and destroy the city, hidden somewhere within.
Harvard University professor Robert Langdon awakens in a hospital room in Florence, Italy, with no memory of what has transpired over the last few days, but being plagued with hellish visions. Dr. Sienna Brooks, one of the doctors tending to him, reveals that he is suffering from amnesia as a result of a bullet wound to the head. Another doctor says the police are there to question Langdon but the officer turns out to be Vayentha, an assassin, who shoots the doctor while heading down the hall. Sienna helps Langdon to escape, and they flee to her apartment.