Elements
The elements, Earth, Air, Fire and Water, form essential plot elements. The clues left on Path of Illumination point to these elements. Each of these elements is represented in religious artifacts in that particular location, the earthly tomb, air blowing angels, firey angel and water fountains. Ironiaclly, these elements are used to murder four cardinals, by suffocating with earth, by puncturing lungs, by burning and finally by drowning. As if to reinforce the imagery, all the cardinals are branded with the name of the element that is used to murder them. The imagery is strong and is bound to leave a long-lasting impression.
Tombs
Robert Langdon is claustrophobic and finds it uneasy to enter tombs and is almost killed when he is trapped inside a sarcophagus. The image this forms is of being trapped and helplessness and raises tension in the plot. The tombs again come in the scene, when Ventresca rushes to Peter's tomb to get antimatter. This time the feeling is of rushing to the centre of problem and solving it, resolving the helplessness of the situation.
Churches
The major plot int he book is the debate between Science and Religion. As the book is based in Vatican City, Italy, a place with maximum number of churches, Robert is bound to feel overwhelmed by the presence and hold of religion around him. The Vatican City is supposed to be the epicentre of religion, which is why it is aimed for destruction. This aspect of the plot almost signifies the destruction of religion.
Angels
Angels occur frequently in the book as they are supposed to guide a person along the Path of illumination. The angels also symbolise the hope that Robert accesses for getting to know the right direction. The angels define a path of correctness and in hsi journey a sight of angel is reassuring and a confirmation that he is on the right track.
