Because of Kistner is narrated from Ben's perspective. He is running towards Sammy but has a hard time because the sutures from his bullet wound are coming open. He begins hallucinating about his sister Sissy and imagines that she is there with him.
Ben has to crawl his way down the hallway with great difficulty. On his way, he encounters the dead guard who Cassie murdered. Ben grabs the dead man's gun and puts on a surgical mask. He almost reaches the room when he sees Sammy come out, followed by someone in uniform. Ben doesn't realize that it's Cassie, Sammy's sister, in disguise.
The Black Hole returns to Cassie's point of view. Cassie notices that Sammy is wearing a silver locket and is intrigued. Sammy tells Cassie that a plane of non-essentials is being evacuated tonight and Cassie lies to Sammy, saying that Dad is waiting for them back at Camp Ashpit.
Cassie encounters Ben, but neither recognizes the other. They both draw their guns and remorselessly think that the other person is toast. They are about to shoot when Sammy recognizes Ben and pulls down his mask. Cassie is shocked and has to remind Ben that they went to the same high school.
Cassie and Ben start to argue about who is rescuing Sammy. Sammy solves the problem by saying they can leave together. They realize that Ben is not doing well and bleeding a lot. They take out Sammy's implant and quickly realize that they both know the same information and are on the same side.
Just then, Vosch finds them. He takes Sammy away and hooks him up to a chair while Ben and Cassie watch. Vosch details the grand plan of the Others and how they have watched humans for millennia. Vosch reveals that he was impressed that Cassie was able to beat Wonderland by hiding her true memories and wants to know who taught her how to do it. Only an insider, an Other, could have told her how since that is how the Others have escaped detection.
Vosch pushes the button that would kill Sammy, but doesn't realize that he doesn't have the implant anymore. Cassie takes out the guard in Sammy's room, realizing that Evan is in the ventilation grate above. Everyone is reunited and introduced. Evan wipes out the power grid, plunging the base into darkness and leads them out.
Evan stays behind to buy them time and says for them to wait for the plane to leave before running for cover. Cassie and Ben have a hard time getting up the stairs because of Ben's injury and they have a difficult time getting past the debris up top as well. They finally do and take off running after the plane goes up.
Cassie falls with Sammy, and Ben picks up Sammy and they keep running. However, Cassie falls again and struggles to get up. A Humvee pulls up, full of Ben's squad friends. Ben throws Sammy to them and goes back to help Cassie. They just make it to the Humvee before the hole in the ground that has opened up collapses even more.
They all ride off away from the base together. Ben kisses Cassie half on the mouth, half on the cheek. Cassie finally asks him if he remembers their conversation on the school bus about their newborn sister and brother, respectively. He doesn't.
These chapters demonstrate just how far Ben has come as a character. He has grown immensely throughout the course of the book, growing from a popular high school football star into an honorable man. He ran away when his sister died in the arms of robbers, but now, with Nugget, Cassie's little brother, he promises that he won't make the same mistake. He has learned from his mistakes and will make the right decision, no matter the cost to his personal safety.
After the squad and Cassie succeed in rescuing Sammy, Ben criticizes Ringer for coming back for him. He says that they might be the only people who know about the fifth wave and that it was reckless of her to risk all their lives for just one person.
However, Ringer points out that Ben did the same for Sammy. While Ben may be willing to risk his life, he does not have to do so alone. The only thing that humanity can do is band together, no matter how much they might not trust one another, or want to survive. They must have each other's backs or no one will survive.
In addition, the actions and words of Vosch illustrate the way the Others view the humans. They are expendable inhabitants of a planet that the Others need to survive, and thus can be eliminated. However, Evan's actions and words foreshadow a possible conflict and aid for the humans in the next two sequels.
Evan opens up the possibility that there are factions and disunity among the Others as well. So far the Others have seemed like a perfect, monolithic, well-oiled machine, but through Evan, we now know that this is not the case. This gives the humans even more reason to hope that they can defeat the Others in some way.