The plot of Angels and Demons has been slightly manipulated for the tour to begin in Piazza del Popolo and finish in Piazza S. Pietro where much of the drama occurred .This should make it possible to gain access to the churches of S. Maria del Popolo and S. Maria della Vittoria before closing time. Piazza del Popolo is dominated by the Egyptian obelisk with its symbols of the Chigi family, hills and a star, and inside the church of S. Maria del Popolo is the Chigi Chapel, once known as the Capella della Terra. The chapel with domed cupola was designed by Raphael and the wealthy Sienese banker Agostino and his brother Sigismondo were buried in Santi's tomb. The great-grandson of Agostino became Pope Alexander VII, whose patronage of Bernini included the statues of Habakkuk and the Angel and Daniel and the Lion. This was where Langdon experienced the gruesome sight of the corpse of Cardinal Ebner branded with the letters of the element EARTH.

Influenced by Milton’s poetry "Let angels guide you on your lofty quest" – Langdon then followed the direction pointed by Bernini’s angel and set off for St. Peter’s Square. This was the scene of the demise of Cardinal Lamassé, the second victim, branded with the letters of the element AIR. Manipulation of the plot allows us to delay the return to St. Peter’s Square where the next clue is located. Bernini’s West Ponente pointing due east in the direction of S.Maria della Vittoria. There are many possible routes from Piazza del Popolo but once we reach the Cornaro Chapel there are further examples of Bernini’s sculpture. These represent members of the Cornaro family as if they were in a theatre box watching the scene of the Ecstasy of St. Theresa. During his late night visit Langdon was soon confronted by the sight of the branding of the element of FIRE on the chest of Cardinal Guidera. The spear of fire of Bernini's angel then led him in the direction of the church of S .Agnese in Agony in Piazza Navona, our next destination.

On the way, we pass the Pantheon, the location of a false alarm early in the plot. The patron for Bernini's Fountain of the Four Rivers was Pope Innocent X and the Pamphili family symbols of the dove and the olive sprig can be seen at the top of the obelisk. The church of S. Agnese merely provides a back-drop for the dramatic scenes culminating in the death of Cardinal Baggia with the letters the element WATER branded on his chest.

The next destination is Castel S. Angelo where Langdon entered the Church of the Illuminati and the ramparts provide a down river view of Isola Tiberina. The Passetto, or Papal Corridor is easily located and it provides a route through the Borgo to St. Peter’s Square. Once we reach the obelisk the walk has been completed and now is the moment to gaze to the heavens and let the imagination flow through the final stages of Dan Brown’s novel.