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
Sissy leaves Ben’s thoughts and he recovers. As he heads toward Nugget, he comes across the corpse of a lieutenant who was shot in the head at close range. Finally, Ben arrives and sees Nugget holding a teddy bear. But a recruit with an M16 is escorting him somewhere. Ben feels that the only way to protect Nugget is to take out the recruit, so he prepares to fire first.
It becomes clear that Ben’s determined efforts to help Nugget are in part his way of coping with the guilt he has related to Sissy’s death. This passage builds suspense because the teddy bear is a sign that the “recruit” with Sammy/Nugget must be Cassie in disguise—and both Cassie and Ben are willing to use force to protect Sammy.