chunk: While Vetra studies Silvano's diaries, Langdon, Olivetti and Vincenzi locate the third church, Santa Maria della Vittoria, and arrive to see Cardinal Guidera, branded "Fire" and suspended above a burning pile of wood. A gunfight erupts between the assassin and the officers, with Olivetti and Vincenzi being killed in the process. Langdon manages to escape, but not before being spotted by the assassin. Langdon convinces two Carabinieri officers to take him to the next location and the trio race to the Water altar, the Fountain of the Four Rivers, just as the assassin arrives in a van. The assassin murders the officers and drops a bound and weighted Cardinal Baggia into the fountain before bidding farewell to Langdon and driving off. With the help of bystanders, Langdon rescues the cardinal, who tells him the Illuminati's lair is Castel Sant'Angelo. There, Langdon and Vetra discover a hidden passageway leading to the Vatican, being used as a hideout for the assassin. Discovering a case