It's Pete's birthday and the old gang from uni are throwing a party. But his head begins to spin as one by one his friends slowly turn against him. He can't work out: did he do something wrong? Is he paranoid? Or are his friends the sick ones?Pete returns from a stint abroad working with refugees. He's tried to move on from his former days of youthful indulgence and now wants to settle down with his girlfriend: the grounded and socially conscious Sonia. His old friends are delighted to have him back and invite them both to a weekend away to celebrate Pete's birthday, catch up, reminisce and get to know Sonia.Whilst Sonia is grounded, smart, principled and socially conscious, the same cannot be said for Pete's old friends, some of whom he has not seen in years. Archie is still taking drugs and making inappropriate jokes and Claire (Pete's ex) seems just as fragile and aimless as the student Pete used to date. Although George and Fig have established careers, and are kindly hosting the weekend, something about their cruel sense of humor seems wholly immature and stuck in the past.It all makes Pete uncomfortable as he braces for the awkwardness of Sonia's arrival the following day. She barely knows them at all and her ordinary background and skepticism of the privileged classes is sure to clash with the clientele of the party.To complicate matters, Pete's friends have spontaneously invited a somewhat feral stranger (Harry) from the local pub, to partake in the festivities. Harry is dangerously unhinged and a pure force of nature who proves a source of entertainment for everyone. Everyone except for Pete who scorns this as the kind of outlandish (and frankly, he thinks, patronizing) escapade they might have all enjoyed back at university.Things go from wild to weird over the course of the weekend and Pete must fend for himself and his sanity amidst revelries that descend into drug-fuelled debauchery. Not only that, but the atmosphere brings about a surreal dismantling of social niceties. Fig brings Pete aside to meticulously list all the awkward moments and faux pas he has had since his arrival. Archie accuses Pete of stealing his drugs. Pete is shocked to learn that Claire tried to kill herself recently. Later, Claire leaves the party claiming it was something Pete said. Even George, closest to Pete, eventually turns against him.And it seems like at the center of the pandemonium is Harry. Like he's intent on causing mayhem and inflicting cruelty. But why should he have it in for Pete? It's eerie, but Pete feels like maybe they've met before.When Sonia eventually joins the party, it momentarily feels like Pete might have found his relief, but slowly the friends turn Sonia against him too. Soon enough, the atmosphere goes from uncomfortable to terrifying, to downright surreal. Pete's mental state deteriorates as moment by moment he frantically navigates a maze of confusion: is he paranoid? Is he being punished? Or is this all part of some sick joke?