The second half of the 5th wave was focusing on a theme of how resilient people can be and how just a sliver of hope can go a long way. This is shown in the main character, Cassie‘s persistence to continue to fight for the human race. Once the main character, Cassie, finds out Evan Walker who is another important character, is actually the one who shot her and that he is actually an alien,the whole book is flipped on its head.