Plot
One year before the events in The Enemy , an unnamed user posts a video on YouTube titled "The Scared Kid", in which a boy frantically talks to the camera about how his friends Danny and Eve have been killed by "mothers and fathers" (zombies) and shows them standing outside his window. He then suffers a nervous breakdown and ends the video. The video goes viral, with people not knowing if it is real or not. Eventually the video is taken down, followed by the site itself, followed by the internet, and finally electricity entirely. This marks the point that people realize that something bad is going on, and signals the start of the apocalypse.
Two weeks into the apocalypse, two 14-year-old boys, named Jack and Ed, are trapped with a group of other schoolboys in a boarding school in Kent, where they are defending themselves from their now-zombified teachers. After escaping with the help of a rugby player named Bam, Jack and Ed rescue their French teacher's daughter, Frederique, and make their way to a nearby chapel, where a group led by a boy named Matt barricaded themselves inside a few days prior. Alarmed by the lack of a reply from inside the chapel, they break in and find that those hiding inside have either fallen unconscious or died from carbon monoxide poisoning.
The group manages to revive the survivors, and Matt appears to have suffered brain damage from the poisoning. He believes himself to be the messenger of a being called the Lamb, who he explains will come down to earth and cleanse it of "nonbelievers" (the zombies). He is convinced he must go to St Paul's Cathedral to fulfil the needs of his "god". The group splits, with Matt and some survivors he has brought into his religion attempting to go to London with Jack (who wants to find his family home), and the rest (including Ed, Bam and one of Ed's best friends, Malik) deciding to go deeper into the countryside (thinking it will be safer).
Ed's group is ambushed by older, infected teenagers, who kill half the group, seemingly including Malik. They are saved by the timely arrival of a motor coach driven by an adult named Greg Thorne, who claims he is immune to the disease. With his young son Liam, Greg has acquired the motor coach and is collecting children to transport them all to London. He and Liam want to visit Arsenal Stadium, unaware that it is an adult nest. On the bus, Ed's group meets three girls, Aleisha, Courtney and Brooke. Brooke immediately develops a crush on Ed, whilst Greg eventually catches up with Matt's group, who are all still journeying towards London.
After finding the others and picking them up, Greg explains that, before the apocalypse, he was staying with a farmer and his family, but he had to kill the father and the older children. He says a younger child, who'd gone crazy after losing his family, "didn't make it", indirectly revealing that he had killed the boy and made him into the dried meat he was seen eating. After a close call where Greg nearly leaves Jack and Frederique behind to a group of zombies, the motor coach stops for the night on the outskirts of London. Liam finds out that Greg is infected, and knowing that he cannot protect him anymore, Greg strangles and kills him.
The next morning, Ed finds Greg inexplicably wearing Liam's glasses. Jack and Ed confront him about Liam's death. This causes him to succumb to the virus, which is revealed after Jack, who gets mad at the discovery, attempts to disarm a shotgun that Greg is wielding. The arm-to-the-face maneuver that he inflicted causes Greg to crash the motor coach. Afterward, he completely succumbs and attacks the kids whilst the bus is simultaneously assaulted by several adults. Most of the group escapes and makes it to the Imperial War Museum in South London. Greg wanders off into the streets, whilst the "Bus Party" meets the museum's leader, Jordan, and his second in command DogNut (who develops a crush on Brooke). Jordan refuses to let them stay, eventually compromising and letting them stay as long as they collect food for themselves.
The group sets off, finding a Tesco truck full of non-perishable food. Whilst they are attempting to get the truck to run, Frederique is surrounded by several adults. The other kids fight off the adults and are surprised to find that Frederique is unharmed. Whilst they are driving the truck back to the museum, Jack and Bam tell Ed that they are planning on going to Jack's old house and hop out to go off on their own. Ed eventually decides to join them, kisses Brooke and catches up with the two boys, unaware that they are being followed by a now fully-zombified Greg.
Meanwhile, back at the museum, Matt's religion has gained more believers. Matt foretells that the Lamb will look like a blond boy and will have a darker shadow; another boy, nicknamed "The Goat", must be sacrificed so that "The Lamb has no shadow" and is capable of cleansing the earth. Frederique attacks a young boy named Froggie, biting into his arm. She reveals to Ed that she is 16 years old and is infected, but her disease took longer to manifest than it did for others. Several of Jordan's kids lock her in a storeroom.
Jack, Ed and Bam make their way to The Oval cricket ground, finding dozens of emergency vehicles outside filled with dead bodies. Despite Ed's hesitation, Bam and Jack kill two soldiers and a policeman. The boys explore, finding and keeping several weapons. They find that the stadium is full of diseased corpses that were stacked to be burned, as well as numerous bodies seated in the stands, but the law enforcement and medical officials were themselves killed or succumbed to the infection before they had a chance to finish the job. The boys learn not all the bodies are dead and are then pursued by adults through the stadium. Jack accidentally shoots a propane tank with a submachine gun whilst trying to fend off an attacker, causing it to explode and setting off an avalanche of corpses. Ed is buried underneath the bodies whilst Jack and Bam are buried underneath the debris resulting from a partially collapsed section of the stadium. Bam mistakes Jack for an adult and shoots him with the shotgun that he had recovered from Greg. Jack is badly wounded in the side, but able to stand. Ed finds them, and the three boys leave, continuing their trek to Jack's house.
In the street, the group are ambushed by adults whom the three boys manage to kill, but as they do a victory dance for killing the rather large group, Greg appears and kills Bam with a meat cleaver to the head. He then slashes Jack's chest open and cuts the side of Ed's face from forehead to chin. Greg is about to finish off Ed, but flees when Ed mentions Liam's name aloud. Ed drags a fading Jack to his home and tries to heal his friend's wounds. However, Jack is beyond repair. Ed takes Jack to his bedroom and keeps him company throughout the night with him. In the morning, Ed finds Jack has died from his injuries. Ed cremates his friend by burning the entire house down, and heads back to the museum under a spreading cloud of smoke and ash emanating from a large fire they'd seen earlier in South London.
Soon, Ed is ambushed again by adults, only to be rescued by David and his group. Together, they all travel to the museum. David warns Ed that the fire is spreading towards the museum, and the group should relocate. At the museum, Ed manages to stitch his cheek, leaving him with a large scar. He confronts Frederique, who has escaped captivity by gnawing off her own thumb to slip out of her handcuffs. Ed defeats her and, against Jordan's advice to kill her so she won't kill someone else, manages to banish her into the streets. Ed holds council with David and Jordan, with Ed and David deciding to move to North London. Jordan decides to stay in the museum with his original group.
Ed and David make a deal: in exchange for receiving food from the Tesco truck, on which Ed's group will ride, David's group will accompany the truck on foot, clearing the congestion and debris blocking the truck's path. Armed with additional weapons from the museum, Ed and David lead their respective groups and attempt to cross the Lambeth Bridge. Every other kid in South London is also trying to cross the river, and they all struggle to do so due to congestion and a commotion between kids further up the bridge. A huge wave of infected adults comes up behind the kids from the south, and Ed and several other fighters, including Courtney and Aleisha, hang back to fend off the infected whilst Brooke and the others drive on. Brooke decides to split off from David's group after she sees him shoot a boy in the chest. Frederique reappears and attacks Aleisha, injuring her, resulting in Ed shooting Frederique dead with a pistol. Ed is helped by another boy named Kyle, and although the fighters initially seem to be overwhelmed, they are rescued by Jordan, DogNut and their his crew, who had been forced to abandon the museum.
The fighters flee, but the way back to the bridge is blocked by a horde of adults. The kids manage to take control of a sightseeing cruise boat moored in the river. They pilot it downstream towards the Tower of London, but Matt hijacks the boat in an attempt to reach St Paul's Cathedral. He accidentally crashes the boat into the bridge and it splits in half, causing a number of kids to drown, including Aleisha. Matt and his surviving acolytes are last seen disappearing under a bridge, standing on the top of half of the ruined boat.
Jordan, Ed, Kyle and the survivors find lifeboats and navigate them to the river's north bank. They make their way to the Tower and enter it by climbing the drainpipes. Inside, they find a group of about thirty kids already inhabiting the castle. Frustrated with the current leader, Jordan takes control, with Ed as his right-hand man. Of the original group from the bus, only Ed and Courtney remain. The others are either dead, missing or still with the Tesco truck. Meanwhile, Greg finds himself in Trafalgar Square and puts on a St. George T-shirt from a souvenir stand, deciding to get revenge on those he holds responsible for Liam's death. It is also revealed that he intends to raise an army of adults, revealing him as the "Saint George" adult from the previous novel.
One year later, DogNut decides to leave the Tower with a group of people, including Courtney, to search for Brooke and the other kids. A few days after this, Ed, Kyle and Jordan witness Small Sam and the Kid arrive at The tower, and are shocked to find that they look identical to the Lamb and the Goat children from Matt's prophecy.
