LitCharts assigns a color and icon to each theme in The 5th Wave, which you can use to track the themes throughout the work.
Trust and Belief
Survival and Perseverance
Warfare and Dehumanization
Family
Summary
Analysis
Evan is still passed out at dawn, and Cassie isn’t sure whether she wants him alive or dead. She figures he must be biologically human but isn’t sure if he’s a traitor. By the time he finally wakes up, Cassie has decided not to kill him. She helps take out the shrapnel.
In this passage, it doesn’t seem that Cassie really wants Evan dead—she just wants freedom from the responsibility of having to make a decision. Often for the characters in this novel, the most difficult part of survival isn’t the circumstances they face but the decisions they have to make in response to their circumstances.
Active
Themes
Cassie asks Evan why he shot those kids on the highway, and he says he didn’t know they were kids. Cassie wonders aloud about how if Earth was dying, humans might be ruthless with the inhabitants of another planet to survive. She doesn’t want to be a “shark” like that. Evan says that she isn’t like that. Cassie notices that he’s deliberately saying “you” and that this is his way of finally telling her he’s an alien. He says he’s not her enemy, but Cassie runs off into the woods.
Cassie’s relationship with Evan is tumultuous as she continues to go back and forth between trust and doubt with him. A shark is an example of a creature that has to be violent and keep moving to survive. Although Cassie sees herself as forced to be a shark in her current circumstances, this way of living could also apply to the aggressive invading aliens. Evan seems to acknowledge this when he says “you,” meaning that both Cassie and humanity in general are less shark-like than the aliens—implying that he himself is an alien.