chunk: Langdon listens to the Illuminati's message and deduces the four cardinals will die at the four altars of the "Path of Illumination", marked by statues of angels in locations relevant to the four classical elements. Over the objections of Commander Maximilian Richter, head of the Swiss Guard, but with McKenna's consent, Langdon is granted access to the Vatican Secret Archives. He examines Galileo Galilei's banned book with Vetra. Following the clues and accompanied by Inspector General Ernesto Olivetti and Claudio Vincenzi of the Vatican Gendarmerie Corps, they arrive at the Chigi Chapel in the Church of Santa Maria del Popolo. There they find Cardinal Ebner dead, suffocated with soil and branded with an ambigrammatic word "Earth". They verify the second location is the crowded Saint Peter's Square and arrive just as a bloody Cardinal LamassĂŠ emerges with his chest branded with "Air". Vetra unsuccessfully attempts to perform CPR on him, only to discover his lungs had been punctured,