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
Cassie dreads having to confront Evan about what he does at night. She decides not to tell him, since if he turns out to be a different person than he claims to be, he might kill her to keep his secret safe. That night, when Evan leaves, Cassie searches the whole house for the first time. She finds family photos of people who look like the family members Evan described, and she starts to feel a little better.
Even after kissing Evan and falling asleep next to him, Cassie isn’t sure if she can trust him. Although this reflects the extreme circumstances that she lives in, where a person who seems to be a human might be a literal alien, it also reflects a more mundane reality of growing up, where romance and relationships bring both excitement and uncertainty.
Active
Themes
Still Cassie has doubts, so she decides to look in one last place: Evan’s barn. She notices something catching the light and pulls up some blankets to find her M16 with her initials in it, which she thought she lost on the highway median. This frightens Cassie, but as she runs out of the barn, she runs right into Evan.
Evan’s attempt to hide Cassie’s M16 recalls when Vosch confiscated the weapons at the refugee camp. The fact that Cassie’s initials are on the gun show how it has become an extension of her—for better or for worse—just as Ringer advised Ben during marksmanship practice.