In 2002, at Ladbroke Grove, Katie, a schoolgirl, endures relentless bullying from a circle of girls and from Sam Peel, a persistent bully who sharpens the threat with a chilling warning: if she tells anyone, he’ll kill her. When her father comes to fetch her after school, Sam’s threat hangs in the air. That evening, Katie’s older brother Lenny Rafe Spall slips into her room and confronts a tragedy no one saw coming: Katie has hanged herself, a devastating shock that sends ripples through the whole community and marks the start of a long, painful chain of events.
The next morning, the news spreads through the school, and students are given the day off to mourn. Trevor “Trife” Hector [Aml Ameen] and his closest friends, Jay [Adam Deacon] and Moony, decide to spend the day escaping the weight of reality by smoking weed and drinking. Meanwhile, Trife’s pregnant ex-girlfriend Alisa [Red Madrell] chooses to spend the day with her best friend Becky [Jaime Winstone], each of them navigating their own complicated feelings in a world that feels quickly out of control.
Becky uses a grim shortcut to score drugs—trading sex with an older man—and she drags Alisa into the vice, pulling her deeper into the night’s haze. The group heads to Sam’s estate to reclaim a Game Boy Sam had stolen, but they also walk away with Sam’s cannabis. In a heated moment, Jay has sex with Sam’s girlfriend Claire [Madeleine Fairley], while Sam returns sooner than expected and is beaten unconscious by the group; in their panic they even knock down Sam’s mother as they flee the scene.
On a train, Alisa and Becky unexpectedly cross paths with some of Katie’s former bullies. Alisa, wrestling with guilt for not being there for Katie, scolds the girls, while Becky inadvertently reveals Alisa’s pregnancy—a detail the bullies threaten to broadcast around school to humiliate her. At the next station, Alisa hurries off to vomit, and Becky mocks her, underscoring the fragile, unspoken tremor beneath their fragile alliances. They finish their shopping for party dresses, then meet up with the boys and head toward a party later that evening. Jay, swayed by Trife’s insistence that Alisa’s baby isn’t Sam’s, tells her that Trife wants nothing to do with her, a notion that leaves Alisa torn and more vulnerable. Desperate, Alisa asks Becky to leave, but Becky insists on going to the party anyway.
Meanwhile, Trife pays a visit to his Uncle Curtis [Cornell John], who hands him a revolver—the same weapon Trife had drilled the barrel for earlier at school. In the downstairs, a debtor named Andreas is tied and beaten by Curtis and Trife after missing a drugs payment. Curtis then orders Trife to carve a “C” into Andreas’ face with a Stanley knife as a brutal test of loyalty. Terrified but obedient, Trife completes the act and flees, haunted by what he’s done. He tries to reach Alisa, but his attempts go unanswered. On the way home, Alisa meets a classmate and persuades her to come to the party. At the party, Becky is stood up by Moony and the group’s efforts to persuade Jay to sleep with her fall flat.
The party takes a turn when Trevor reveals his feelings for Alisa as the two kiss outside. Alisa confirms that the baby is definitely his—as she had never slept with Sam. The pair rekindles their bond, but Sam arrives and attacks Trife. Alisa and the others intervene, while Jay and Moony try to keep him at bay. Outside, Sam beats Trevor and Jay, and he tries to intimidate Moony into staying out of it. Alisa, the one who remains fearless in the face of Sam’s aggression, slaps him, and Trife rises to defend her. Sam grabs a baseball bat and delivers a devastating blow to Trife’s stomach, a wound from which Trife will not recover.
As this chaos unfolds, Lenny arrives at the party with a gun, forcing Sam to the ground and presenting Katie’s note. Lenny intends to kill Sam, but Trife, in a final, selfless moment, stops him, telling him that Sam is not worth it. Sam insults Lenny as Lenny begins to walk away, and the gun fires feebly, the weapon failing to do its work. Sirens begin to wail in the distance, and Lenny, his accomplice, and Sam all flee the party as Trife dies, with the ambulance and police arriving only after the heartbreak and violence have unfolded.
