American symbologist Professor Robert Langdon (Tom Hanks) is brought to the Vatican to help. He deduces that the four cardinals will be murdered on the four altars of the "Path of Illumination", in locations relevant to the classical elements. McKenna gives Langdon access to the Vatican Secret Archives to research the altars, against the wishes of Commander Richter (Stellan Skarsgård), head of the Swiss Guard. He and Vittoria examine Galileo Galilei's banned book, following clues to the Chigi Chapel, accompanied by Ernesto Olivetti (Pierfrancesco Favino) and Claudio Vincenzi (David Pasquesi) of the Corps of Gendarmerie of Vatican City. They find Cardinal Ebner dead, having suffocated on a mouthful of dirt and branded with the ambigrammatic word "Earth".