The main characters of the story are as follows:
Robert Langdon - Professor with good knowlege of the Illuminati
Illuminati - A group against the Roman Catholic Church claiming to be advocates of science and believed to be extinct.
Maxmilian Kohler - Director of CERN, known better as the Hadron Collider, experimenting to make Antimatter, Boson or God particle or what ever you want to call it.
Lenardo Vetra - Priest and sceintist working for CERN
Vittoria Petra - Lenardo Vetra's adopted daughter
Carlo Ventresca - Camerlengo of the Vatican, a priest who was the pope's secretary and assumes the position as high as an acting pope during conclave, the period during which a new pope is elected after a pope's death
Antimatter - Matter that acts in an opposite manner to the existing matter in the universe. These are supposed to have extreme power and is not known to have been produced in quantities greater than nanograms. It cannot exist for long and will disappear by coming into contact with matter releasing energy of magnitudes that we have not known before.
The story goes as follows:
Lenardo Vetra in the course of his experiments creates Antimatter and stores away about a quarter of a gram in a specially designed canister. The canister is powered by special magnets and the Antimatter is suspended inside the canister. If the magnets does not get its power the Antimatter will cease to suspend and come into contact with the cannister exploding with more power than an atom bomb.
The Illuminati murdered Lenardo Vetra and stole the Antimatter which they then planted deep inside the Vatican. Having lost its electrical supply the canister will explode within 24 hours after the rechargeable batteries in the canister are exhausted.
Max Kohler calls Robert Langdon for help. Ms.Vittoria joins him in the quest to locate the Antimatter in the Vatican. When they arrive they also learn that 4 cardinals who were the most likely contenders to be Pope have been kidnapped. The killer hired by the Illuminati threatens to kill them, each hour in the late evening.
Father Carlo Ventresa is in charge of the conclave as customary and after every attempt to locate the Antimatter decides to cancel the conclave. He gives a fiery speech condemning the Illuminati, and increasing the faith and determination of all Catholics which is broadcast live to the entire world.
When the Illuminati killer succeeds in killing the cardinals every hour, Robert Langdon and Vittoria desperately follows Illuminati symbols and finally suggests the location of the antimatter. However it was Father Carlo Ventresa who finally finds it guided by a message from God. Having found it deep underground, He takes it to the sky in a helicopter and parachutes himself to earth. The antimatter explodes and no life is lost.
The cardinals suggest that Father Carlo Ventresa should be Pope. Though he is just a priest, the occasion is considered exceptional and everyone agrees. In the last moments the true face of the assassin surfaces. The person behind the chaos, the stealing of the Antimatter and the murder of the cardinals was one damn conspiracy. This is the climax of the story.