The Infinite Sea

The Infinite Sea (2014) by Rick Yancey is a young adult science fiction romance novel. It is the second book in The 5th Wave Trilogy, following The 5th Wave (2013) and preceding The Last Star (2016). The trilogy follows protagonist Cassie Sullivan, a 16-year-old girl who survives an invasion by extraterrestrials known as the Others. In the first novel, she meets Evan Walker, a Silencer (a human whose body has been colonized by the consciousness of an Other). As the two fight their conflicting feelings and deal with the aftermath of an invasion that has killed 97% of humanity, Evan helps Cassie free her younger brother, Sammy, and a group of child soldiers being trained to kill the few remaining humans. As Cassie, Sammy, and the freed members of his squad—known as Squad 53—escape, Evan stays behind to ensure the destruction of Camp Haven and the Others’ command base.

The Infinite Sea picks up where the first novel left off, as Cassie and the others wait in a nearby hotel for Evan to join them. The group argues over their next move, with Ringer deciding that they should explore the nearby caves where there are rumored to be humans living. However, when Ringer leaves the group, she and Teacup are taken by Vosch, the leader of the Others’ forces on Earth. The novel alternates between Ringer, who struggles to understand the motives of Vosch and the Others, and Cassie, who is joined by Evan and hunted by another Silencer named Grace. Through their stories, the novel explores themes of Love as Both Strength and Vulnerability, Compassion as a Defining Element of Humanity, and The Value of Hope in Seemingly Hopeless Situations.

This guide is based on the 20th paperback printing of the novel published by Penguin Books.

Content Warning: The source material and this guide feature depictions of child death, suicidal ideation, alcohol use and addiction, graphic violence, sexual content, cursing, and death.

Plot Summary

Cassie, Ben, Ringer, Sam, Poundcake, Teacup, and Dumbo are in a nearby hotel after the destruction of Camp Haven, a former US Air Force base that had been repurposed as a training facility for human children trained to kill other humans. Cassie is adamant that they need to wait for Evan, as he has promised to return to them after facilitating the camp’s destruction, despite Ringer and Ben’s hesitancy to trust him. Ringer decides to leave the group to scout out nearby caves where there are rumored to be surviving groups of humans.

Ringer makes her way to the caves outside the nearby city of Urbana. She is unsure how she feels about Evan. Although she trusts Cassie’s story, she can’t understand how Evan would abandon his “Other” identity and the years they put into invading planet Earth.

Ringer finds a dead soldier against a tree. As she contemplates what danger she is in, she spots someone following her. She shoots the person, then recognizes her as Teacup, a seven-year-old girl who followed her from the hotel. Devastated, Ringer realizes that she does not have the tools to save Teacup’s life. However, at the same time, a helicopter descends on them. Instead of fleeing, Ringer allows the helicopter to take both her and Teacup.

Back at the hotel, Cassie and Ben discover that Teacup is gone. They send Poundcake out to find her. After he fails to return, they realize that Dumbo is gone as well. They decide to check the lobby, with Ben taking the stairs and Cassie the elevator shaft.

Cassie waits for the signal from Ben that he made it to the first floor. After several moments, she leaves the elevator and, not finding Ben, makes her way up the stairs. Partway up, she hears gunshots. She finds Ben injured in the hall, then finds an intruder in Sam’s room. After shooting him and pinning him to the ground, Cassie realizes that the intruder is Evan.

The narrative then shifts to Evan’s time since escaping Camp Haven. He comes across Grace, an Other he met when he was a child. After their Other consciousnesses “awoke” within them at the age of 13, they met at a fair, then spent the day together. The experience confirmed for them that their memories were not delusions and they were actually an alien species. Now, years later, they meet again. However, Grace is hesitant to trust Evan as he tries to explain what happened at Camp Haven. She realizes that he has fallen in love with a human. In the end, Evan strangles Grace and flees, making his way back to the hotel.

In the present, Evan lies unconscious on the floor as Ben and Cassie debate what to do. Suddenly, a young girl appears in the hallway. Sam excitedly greets her, calling her “Megan” and telling them that he was on the bus with her on the way to Camp Haven. Megan tells them that her throat hurts, then collapses. Ben and Cassie drag her into the room and are going to wake her up. However, before they do, Evan regains consciousness and warns them against it.

Evan explains that Megan has a bomb in her throat. It is designed to explode when it detects too much CO2. He helps Cassie remove the bomb, then they place it in a plastic bag to keep it safe. After discussing what Vosch’s plan was, Evan points out that because the bomb didn’t explode, Vosch now knows that Evan survived and is with them—since only Evan could have warned them about the bomb. They make a plan to detonate the bomb using a CO2 tank then flee the hotel, making Vosch believe that they died.

As Ben and Poundcake go to retrieve a CO2 tank, Evan and Cassie wait in the hotel. Evan draws a map for Cassie to a house nearby. He warns her that Grace is coming and that they won’t be able to kill her because of her enhancements. As Cassie struggles to understand, Grace appears, holding Dumbo hostage. Unable to stop herself, Cassie attacks Grace. At the same time, Ben and Poundcake return. A fight ensues, wherein Poundcake is shot and Grace barricades herself in a room. Evan begs Cassie, Ben, and the others to run, as he knows that Grace cannot be stopped. He tells Cassie that the map he drew is to Grace’s safe house; at the equinox, an escape pod will come to take her to the mothership. He then gives the bomb to Sam, and Cassie carries him out of the hotel.

Ben, Cassie, Sam, Dumbo, and Poundcake escape. Because of Poundcake’s injury, Ben is forced to carry him. However, he becomes unable to do so, and Dumbo implores him to leave Poundcake behind as he will not survive the gunshot. The group manages to make it to an overpass for cover. At the same time, the hotel behind them explodes.

The narrative shifts to Poundcake’s perspective. After Ben left him, he crawled back to the hotel. He found the bomb inside the bag, which Sam had dropped, then made his way into the lobby. He distracted Grace long enough for Evan to escape, then breathed into the bag and detonated the bomb.

Meanwhile, Ringer and Teacup are taken back to Vosch’s base. Vosch taunts Ringer, asking her questions about the Others while using the Wonderland technology to see her memories. Eventually, Vosch injects Ringer with nanobots designed to augment her system. They will make her stronger, faster, and smarter, putting her on the same level as the Others.

Once Ringer is injected with the nanobots, known as the 12th System, she spends several days recovering. Her body fights the injection, causing her to have a dangerous fever and struggle to eat. Through it all, a recruit known as Razor cares for her. Although he is initially cold with Ringer, the two slowly grow close as Razor begins to believe Ringer’s claims that Vosch is actually an Other. The two develop a way to communicate, then make a plan to escape.

After a month, Ringer finally recovers from the injection. With Razor’s help and her new abilities, she manages to escape her room, find Teacup, and escape the base with a helicopter. She sends Razor out of the helicopter with Teacup, then jumps into a lake as it crashes.

Ringer makes her way to the crash site, where she finds Razor. She kisses him, an act that allows her to read his mind. She realizes that he is hiding something from her. When he takes her to a nearby concrete plant, where he claims Teacup is hiding, Ringer knows that he is lying. She knocks him out, takes her gun, then enters the plant.

Ringer finds Vosch waiting for her. He asks what she has learned about humanity, and she tells him that she has figured out that the Silencers were a lie. They are not truly Others inside of a human body as everyone—including the Silencers themselves—thinks; instead, they are humans who were augmented as she was and were led to believe they were Others. He praises her discovery, then tells her that the escape was a setup to test the 12th System. Ringer tries to kill him, but Vosch incapacitates her. He leaves her in the concrete plant and tells her to recover, then he will come back for her.

Over the next week, Razor cares for Ringer in the plant. Although he initially refuses to talk to her, Ringer finally asks him if he lied about his past. Razor is adamant that everything he told her was true; he only lied to her because he was ordered to do so. The two kiss, allowing Ringer to access his mind. She realizes that he is telling the truth. They then have sex.

After, Razor tries to get Ringer to run. However, she refuses, as she is insistent that she needs to save Teacup. A helicopter arrives and takes the two of them back to the base.

At the base, Ringer and Razor meet with Vosch. Teacup is nearby being held by a guard. Vosch tells Ringer that he is now going to deploy her to find Evan. She tells him that she knows why Evan has become a liability: He has fallen in love, which makes him unpredictable. Suddenly, Razor draws his gun. He shoots Teacup, killing her, then is shot in turn by the guard. As he dies, he tells Ringer to run because she is now “free.” Ringer jumps through the window and to the ground, then runs.

Cassie, Sam, Ben, Dumbo, and Megan hide in the woods. As Sam and Megan sleep, Cassie contemplates what happened back at the hotel. Evan then walks out of the woods, and Cassie runs to meet him.