The film opens with seventeen-year-old Alex Forbes, Eddie Redmayne, a privileged and intelligent student who enjoys thrill-seeking with his friends. After the sudden death of his roommate, Nigel Colbie, Alex Forbes is arrested and charged with murder. Forensic psychologist Sally Rowe, Toni Collette, is assigned to evaluate him and unravel what really happened behind the school’s walls.
Through a series of flashbacks, the audience follows Alex’s perspective as he recalls his time at a secluded boarding school, where a troubling bond forms between him and Nigel Colbie. Nigel—a reclusive, intense figure with an unsettling fascination for death and taxidermy—gradually encroaches on Alex’s life, blurring the line between friendship and control. The pair’s relationship grows increasingly toxic after the suspicious death of a mutual friend, an event Alex believes Nigel may have orchestrated, and the tension between them deepens as Nigel’s influence becomes harder to resist.
Nigel’s manipulation escalates when he helps Alex with an essay and then introduces him to a secret society known as the Brotherhood—a modern offshoot of the Knights Templar. Nigel insists that both of them are destined for a sacred role within this clandestine order, and he marks their bond with a playing card, the Jack of Spades, which bears on its back the inscription “MY BELOVED MARACLEA.” > "MY BELOVED MARACLEA." The symbol becomes a chilling omen that foreshadows the couple’s supposed fate and the rituals they are entangled in.
A later, failed romance with a local girl named Susan Mueller, Kate Maberly, ends in a brutal ritualistic murder. Susan’s body is found surgically dissected and grotesquely displayed, casting a pall over the school and forcing investigators to confront a darker spirituality within the Brotherhood. As the investigation deepens, evidence pointing to Nigel’s fanaticism begins to surface, casting doubt on Alex’s calm exterior and hinting at a shared, disturbing past. The Brotherhood’s lore—a legend about necrophilia and a woman named Maraclea whose grave was desecrated to power a ritual—becomes a creeping undercurrent in the story, and Nigel later tries to pressure Alex into replicating a similar act with Susan’s corpse, insisting that Alex, as Susan’s supposed only love, must complete the ritual to seal their fated union.
Alex’s reaction wavers between denial and fear. He repeatedly asserts his innocence and distance from the cultish demands, yet the mounting evidence— eerie imagery, the growing secrecy, and Nigel’s unspoken threats—casts a long shadow over his guilt or complicity. When the two finally confront each other at the Colbie estate, a chilling cascade of revelations unfolds. Nigel’s parents are drawn into the deadly web: Nigel’s mother is accidentally shot by his father during a tense confrontation, and Nigel himself is later shot by a gun intended for him. Nigel persists with the ritual, burning organs and declaring the union inevitable, while Alex recoils in horror at the incest and necrophilia he’s accused of having participated in. Nigel’s calm, unsettling persistence compounds the tension, and his final words on their “destiny” haunt Alex and the audience alike.
The pursuit ends on a rainy night near the railway. Alex flees with Nigel in relentless pursuit. On the tracks, the two stand at a precipice as a train approaches. Nigel pleads for Alex to move, arguing that their fate is already written, but in a moment of vulnerability, Nigel tackles him to safety. Disarmed, Alex takes the pistol and, with a brutal and final declaration of their unity, Nigel pulls the trigger and ends his own life. The aftermath leaves Alex alone with the evidence of what happened, carefully stowing a red Brotherhood journal, Nigel’s doctor’s case, and a box—strongly implied to contain Susan’s skull—into a bag.
Back in the present, Rowe delivers a lecture at the Ninth Annual Conference of Forensic Psychology, discussing how belief, delusion, and identity can converge into a shared conviction—“a merging of like minds.” Her curiosity is piqued when she receives a sealed envelope bearing the Brotherhood’s insignia, containing a Jack of Spades inscribed with “MY BELOVED SUSAN.” Shortly after, she is summoned to a cemetery where Susan Mueller’s grave has been desecrated, the skeleton rearranged and the skull missing, suggesting that the brotherhood’s reach extends beyond the school’s walls.
The film closes with a stark memory of Alex in interrogation: “Nigel got what he wanted.” When Rowe asks what that was, he coldly answers, “Eternity.” A final image follows, with Alex on a train, seated behind a boy engrossed in a history book. He still carries the red journal and the box, and, in a quiet, chilling moment, he leans forward and asks the boy, “You like history?” The line between history and fate blurs, leaving the viewer with a lingering sense of consequence and the price of a shared dream gone wrong.
