Water

Water is essentially a symbol of destruction. Small amounts, like the water trickling down Mitchell's neck when he is in situations that are somehow self-destructive, manifest this idea more metaphorically, while the water that floods New York, both that falls and rises from the ground because of the storm, manifests it more directly.

Cassandra

The term "Cassandra" represents someone who can foresee the future, and is used in the book to refer to Mitchell, Jane, and others who use statistics and research to do exactly that. The term comes from Greek mythology, in which Cassandra was a princess of the ill-fated city-state of Troy, and was both blessed (with the ability to see visions of the future) and cursed (because nobody would believe her). The use of her name to refer to Mitchell and Jane is somewhat ironic, because they use facts rather than visions to...