Four 19-year-old friends – Joanne, Cassandra, Shannon, and Kerrys from London – all meet one another at a diner, where they spot Dillon and Smoothy. As the police close in, Dillon and Smoothy run off, and in the rush Dillon accidentally drops a stolen diamond into Cassandra’s bag. The four girls part ways for the night, each carrying a sliver of trouble that will pull them back together in unexpected ways.
Shannon returns home just as her mother is leaving her father, and [Joanne] invites Shannon to the 24-hour supermarket where she works with Angelo, only to tell her to leave as soon as she arrives. When Shannon refuses, Dillon kisses [Joanne], which deeply ignites Shannon’s sense of betrayal. In a reckless moment, she grabs a Pringles tube from the shop and flees. Later, after getting drunk at a bar, Shannon is attacked by a gang and rescued by Kelly, who reveals she is hunting for “15 diamonds.” One diamond is already in Cassandra’s bag, while the rest are concealed in the tube that fell from Shannon’s possession during the assault. Shannon manages to escape, retrieves the tube, and leaves a message for [Joanne] about the diamonds. Her pain grows heavier as she tracks down her mother and confronts the belief that she never cared for her, especially after a forced abortion is revealed in the family history. Standing on the edge of a bridge, Shannon contemplates suicide, the weight of the diamonds and family wounds pressing down on her.
Meanwhile, Cassandra travels to New York City to meet Brett, a man she connected with online, and auditions for a piano school. The encounter turns sour when she discovers Brett is a stalker who hacked into Cassandra’s computer and captured intimate videos. After a tense confrontation with a fake Brett, she defeats him and erases the incriminating footage, then retaliates by taking photos of his private parts as revenge. Persevering, Cassandra pressures her way into an impromptu audition with Jago Larofsky and earns a place at his prestigious school. She then heads back to London with a new sense of purpose, telling [Joanne] that she knows where Shannon is.
Back in the city, Kerrys, and her girlfriend Jas, witness her brother Manuel receiving a package containing fresh instructions from Dillon and Smoothy. The two girls break into Cassandra’s home and discover a panic room. Manuel locks them inside, then returns the package to Dillon and Smoothy while throwing a party. The girls manage to escape the panic room, sending everyone tumbling out of the flat. Kerrys returns home to find Shannon’s mother’s letter, which Cassandra had sent, and she begins to mend fences with her father. She then packs a daring plan, locking Manuel in the trunk of his new car and driving off to locate Shannon, only to crash the car into Jo’s shop when Manuel tries to attack her.
Jo grows suspicious of her new manager, Tee, who has been working with Dillon and Smoothy to move the diamonds, though one is missing. The duo returns to retrieve money, but Tee betrays them, keeping the funds for himself and triggering a spree of violence in the store. When Shannon arrives, Jo tries to get her to leave and Dillon kisses Jo, all while Shannon remains unaware that Jo is in peril and a gun is present. Shannon departs with the Pringles tube, unaware that it now contains the fourteen diamonds Tee hid earlier. The next day, Jo realizes Shannon has the diamonds; Tee seems doomed when Kelly steps in, and [Angelo] intervenes to thwart further bloodshed as Kerrys crashes Manuel’s car into Jo’s shop.
Jo acts quickly, helping Kerrys escape and leaving a note and a DVD that implicates Tee. Tee tries to run, but is apprehended after [Angelo] strikes him down and police arrest him. Cassandra returns with the final diamond, and she, Jo, Kerrys, and Shannon team up to track Shannon down. They talk her down, share the letter that explains the past, and offer comfort as a unit. In a hopeful culmination, the four girls reunite the 15 diamonds and hand them over to the police, with Kelly choosing to join them on a flight to New York City to start anew together.
