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
Nugget bunks with Zombie. Their days are fully scheduled with training. At night, Nugget asks Zombie if it’s okay to pray, and Zombie thinks it probably is, as long as it’s quiet. Nugget says he has a sister named Cassie who is coming to get him. Zombie helps Nugget with a prayer that he used to say with Cassie.
This passage reveals that Nugget is Sammy. Sammy’s decision to keep praying at night shows how he still holds on to faith, even after getting separated from Cassie.