Angels & Demons

The plot follows Harvard symbologist Robert Langdon, as he tries to stop what seems to be the Illuminati, a legendary secret society, from destroying Vatican City with the newly-discovered power of antimatter.
CERN director Maximilian Kohler discovers one of the facility's most respected physicists, Leonardo Vetra, murdered in his own secured, private quarter at the facility. His chest is branded with a symbol—an ambigram of the word "Illuminati"—and his eye is dislodged. Instead of calling the police, Kohler researches the topic on the Internet and finally gains contact with Langdon, an expert on the Illuminati. Kohler requests his assistance in uncovering the murderer.

Langdon nevertheless attempts to complete the Path of Illumination in order to find the assassin and rescue Vittoria. His search leads him to Castel Sant' Angelo, that hides an underground tunnel leading directly into the pope's chambers in the Vatican. Langdon frees Vittoria, and together they send the assassin falling several hundred feet to his death. The two hurry back to St. Peter's Basilica, where they find that Kohler has arrived to confront the camerlengo in private. Langdon and Vittoria fear that Kohler is Janus, and that he has come to murder the camerlengo as the final step in his plot against the Church. Hearing the camerlengo scream in agony, the Swiss Guards burst into the room and open fire on Kohler. Just before he dies, Kohler gives Langdon a videotape that he claims will explain everything.

Langdon returns to St. Peter's and views Kohler's tape with the College of Cardinals. Langdon, Vittoria, and the cardinals confront the camerlengo in the Sistine Chapel, where the truth is finally revealed; Shortly before the beginning of the novel, the pope was scheduled to meet with Leonardo Vetra concerning his research at CERN. Vetra, a devout Catholic, believed that science was capable of establishing a link between Man and God, a belief that was manifested by his research on antimatter.

As one final twist, it is revealed that Camerlengo Ventresca himself was the birth son of the late pope, conceived through artificial insemination. Suddenly overcome with grief and guilt at having caused so much death, especially that of his own father, Ventresca soaks himself in oil and immolates himself before a crowd of onlookers in St. Peter's Square. The conclave elects Cardinal Mortati as the new pope. In an ironic twist, through a quibble, a loophole in the papal election process known as election by acclamation, two popes were chosen: Ventresca by all the cardinals cheering his name before he lights himself on fire, and Mortati through normal means.
Langdon and Vittoria retire to the Hotel Bernini. Lieutenant Chartrand delivers a letter and package to Langdon from the new pope. The package is the "Illuminati Diamond" brand, which is loaned indefinitely to Langdon.