The Infinite Sea

The Infinite Sea (2014) is the second book in Rick Yancey’s young adult science fiction trilogy The 5th Wave. In the first book, also called The 5th Wave, aliens known as “Others” have repeatedly attacked Earth in various waves, attempting to destroy the human population. The first attack is an EMP, effectively destroying all of Earth’s technology and instantly decimating half the population. In the second wave of the attack, a series of tsunamis again takes a heavy toll on the population, especially those living along the coast. The third wave is a plague resembling Ebola, a highly infectious disease causing internal and external bleeding, which is first spread via birds and then by infected humans. The fourth wave, and the main subject of the first book, reveals the existence of “Silencers,” or aliens that take over the body of a human host. Silencers have increased strength and endurance, but in all other aspects appear to be completely human; distinguishing ally from enemy is therefore difficult.

Part of the mission of the Silencers is to train an army of child and adolescent soldiers. They provide the trainees with technology that allows them to see which humans are hosts for the aliens. The trainees are also taught that the only way to kill the Other is to kill the host. However, it is revealed in the end of the novel that the technology actually indicates surviving humans, and that the Silencers have been tricking the children into destroying fellow humans.

The protagonist of the first book is 16-year-old Cassie Sullivan, who is attempting to rescue her five-year-old brother from Camp Haven, a militaristic training facility. After an injury, Cassie herself is rescued by Evan Walker, a mysterious boy with unnatural strength and combat abilities, who is revealed to be a Silencer. Other notable characters include Ben Parish, also known as Private Zombie; Sammy, Cassie’s younger brother; Ringer, a female Silencer; and Commander Vosch, the villainous camp commander. Once the true purpose of the camps is discovered, Cassie, Evan, and the surviving members of Ben’s training squad enact a plan to destroy Camp Haven.

The Infinite Sea expands the narrative focus out from Cassie and Ben to include Evan and Ringer. After the group escapes and destroys Camp Haven, the remaining members of Squad 53 find shelter in an abandoned hotel. All except Cassie believe that Evan died in the destruction of the camp, so they are mainly concerned with distancing themselves from Vosch and surviving the winter. Ringer explores a network of caves near the hotel and shoots fellow squad member Teacup, mistaking her for another Silencer. Ringer gives herself up to a helicopter patrol knowing that she will be brought back to Vosch, in the hopes that they can save Teacup.

Meanwhile, Evan wakes up in the home of Grace, another Silencer he recognizes from his youth. Knowing that Grace does not share his sympathies for humans, he pretends to share her distain while he heals and plans his escape. Evan attempts to kill Grace, then flees to the hotel to meet up with Cassie and Squad 53. After he arrives, so does a little girl Sammy recognizes and calls Megan. None of the survivors can go near her, as a bomb implanted in her throat has been programmed to detonate when it comes into contact with the carbon dioxide humans breathe out. This is one of Vosch’s tactics, used when the children he captured were still too young to train. Cassie and Evan manage to surgically remove the bomb from Megan’s throat and seal it in a plastic bag. They plan to use CO2 canisters to detonate the bomb after they are a safe distance away. This will make Vosch think his plan was successful and put him off their trail. However, Grace arrives to try to recapture Evan. Evan knows she won’t stop trying to find him and persuades Cassie and the rest to leave him behind when they escape. They devise a plan to get to Grace’s house and intercept a pod descending from the alien mothership, and plant a bomb in it, in the hopes that when the pod returns to the ship it will detonate and destroy it.

Back at the base, Ringer is essentially held hostage by Vosch, while she is “enhanced” with Other nanobot technology called system 12. Ringer befriends and eventually pursues a relationship with a boy at the camp, Razor, who vows to help her escape. However, Ringer refuses to leave the camp while Teacup is there. Instead, Razor brings her to a barn where she and Vosch fight, and Ringer is beaten. Vosch reveals that silencers are not actually aliens at all: They are human beings enhanced by technology and implanted with false memories of their alien lives in order to make them despise other human beings. The true purpose of the existence of silencers is unclear, though it is made obvious that if the Others simply wanted to destroy all of humanity their technology is more than capable. Razor shoots Teacup so that Ringer has nothing holding her back from escape, and Vosch kills Razor. Ringer dives out of a window.

The others leave the hotel but must abandon one of their own, Private Poundcake, who was shot and injured in the confrontation with Grace. He manages to crawl back to the hotel, and he sacrifices himself by breathing on the CO2 bomb while within feet of Grace. Somehow, Evan manages to survive the explosion and reunites with Cassie in the woods surrounding Grace’s house.