As Langdon races against time to prevent the catastrophic destruction of the Vatican and the murder of four kidnapped cardinals, he uncovers a complex conspiracy orchestrated by the Illuminati, a secret society long thought extinct.
In the climax of the film, Langdon discovers that the antagonist, Camerlengo Patrick McKenna (played by Ewan McGregor), who is the acting Pope following the death of the previous Pope, is the mastermind behind the plot. McKenna is driven by a twisted desire for power and a misguided belief that by staging a crisis, he can unite the world under the banner of the Catholic Church.
Langdon confronts McKenna just as the antimatter, stolen from CERN, is set to explode within the Vatican. With the help of Vittoria Vetra (played by Ayelet Zurer), a scientist who helped create the antimatter, Langdon manages to locate and deactivate the bomb just moments before detonation, saving countless lives.
However, the confrontation between Langdon and McKenna takes a dramatic turn when McKenna reveals his true intentions and confesses to orchestrating the entire scheme. He believes that by becoming a martyr for the Church, he will be remembered as a hero and cement the Church’s authority in the modern world.
In a tense standoff, Langdon exposes McKenna’s treachery to the gathered crowd, including the College of Cardinals and Swiss Guards. McKenna, realizing that his plan has been foiled, flees to the top of St. Peter’s Basilica, where he attempts to escape by helicopter.
Langdon pursues McKenna to the rooftop, where a final confrontation occurs. In a desperate bid to evade capture, McKenna sets himself on fire, choosing death over facing the consequences of his actions.
In the aftermath, Langdon and Vetra are hailed as heroes for their role in averting the crisis. The Church is left to grapple with the fallout of McKenna’s betrayal, while Langdon reflects on the timeless struggle between science and religion, and the enduring power of faith and reason.
The film ends with Langdon departing from Rome, knowing that his adventures are far from over, but with a renewed sense of purpose and determination to continue his quest for truth and justice in the face of darkness and deception.