Mickey Mouse Watch
Robert Langdon's gift from his parents when he was nine-years-old. To this date, this watch is Langdon's watch, it symbolizes his own self. When Robert wakes up in the hospital, he is disoriented and suffering from amnesia. However, he began asking for his Mickey watch, saying that he does feel like himself without it.
Green Eyes
Before Zobrist was introduced by name and background story, he was referred to as the man with green eyes. So, when the narrator refers to green-eyes he is talking about a symbol of Zobrist.
Dante's Inferno
The idea of Dante's Inferno comes from The Divine Comedy which talks about a man's journey through hell in order to find his love, Beatrice and then walk to Heaven. Zobrist used Dante's vision of hell to describe what will happen to earth if the overpopulation problem is not controlled.
The Bag
The bag that contained Zobrist's virus is a symbolism of an hour glass to Robert Langdon and the rest who are trying to stop the virus from spreading. The strength of the bag is unknown to the characters which cause tension to them, since they have no idea how much time they have left before the virus activates.
Elizabeth's Amulet
Elizabeth's amulet was used to foster a trust between Sinskey and Robert Langdon. However, in Sinskey's life in refers to her job in the medical atmosphere and her infertility. The thought of being unable to have children caused her to lose a man that she loved when she told him about her fertility problems.
The Mask of Plague
Throughout the story, plague masks appear, which symbolizes fear citizens have on the plague that Zobrist plans on releasing to the world. In depth, it symbolizes human's fear on a world wide annihilation of the human race. However, Robert Langdon uses these symbols to translate Zobrist's message which led him to find the bag containing the virus.
