Eight-year-old Alex and his friends Samantha, Jean, Mathilde, Renata, Maxime, Douglas, and Dominique gather to watch the Arthur film trilogy, a shared fascination that sparks Alex’s quiet dream of becoming a Minimoy. In the years that follow, the group remains tightly knit, and the story pivots on a simple wish that grows into a daring teenager’s plan: to live inside the world of their favorite films.
Ten years later, the once-wide-eyed boy has become eighteen and finds himself masking his identity as Arthur to outrun the authorities, a twist born from a mix of necessity and imagination. Meanwhile, the others are gearing up for a birthday celebration, preparing for a party that will blur the line between make-believe and real danger. Samantha arrives in an outfit fit for a princess, Princess Selenia, and the moment feels like a spark in a smoky room of growing adulthood. The group marks the occasion with cake and gifts, a small bright note in a journey that will soon reveal the dark undercurrents of their fantasy.
Their curiosity leads them back to the films themselves, and they learn that their friends Momo and Pilou have found the house used as a filming location. Fueled by excitement, they set off to locate the place, stepping into a quiet town where the locals seem to watch every move they make. A house on the edge of town becomes the center of a tense encounter: an inhabitant and his dogs warn them away, firing a shot to push them back, an act that unsettles the travelers but does not deter their mission. A fallen tree blocks the road, forcing the group to press on on foot, while Renata leaves ribbons to guide a way back, a small act of practical hope in an otherwise perilous trek.
Inside the house, they uncover camping gear that belongs to Momo and Pilou, and the group splits up to explore. Maxime and Dominique join the others upstairs, while Alex and Samantha take the basement route, where a blocked door becomes a sign of shared risks. Jean appears suddenly in full film makeup, a jarring reminder that their love of cinema can bleed into reality. The night settles in as the group camps near the house, and the air grows thick with unspoken feelings—the kiss between Alex and Samantha punctuating a moment where affection and fear share the same breath.
Nightmares arrive with the shadows: Alex dreams of Momo, Pilou, and himself under threat, and awakening finds distant lights flickering with no answer in the air. The next day brings hunger and danger in equal measure as their food vanishes; Douglas bravely sets off to fetch supplies, only to fall to the attackers. A cruel turn follows when Maxime and Dominique discover Momo hanging from a tree, and Maxime is ensnared in a bear trap while Momo falls to his death. Dominique frees Maxime and returns to the house with a heavy heartbeat.
The group stumbles upon a hole that seems like a gateway to the Minimoy kingdom, and they lower Jean with a camera to inspect the depths. Something pulls him downward, but Alex acts quickly to cut the rope and pull Jean back to safety. Rising tension gnaws at them as Renata suggests heading home, yet the lure of discovery keeps them moving. After learning that Maxime is injured, Alex, Jean, and Dominique rush to the car to get him to a hospital while they search for Douglas. In the meantime, Samantha and Renata listen to music, and Mathilde, driven by panic, notices an unidentified presence in the house. She barricades herself in a barn, only to be stung by a swarm of bees summoned by the intruder above.
The truth behind the violence surfaces when Douglas is found dead, his fate sealed by a brutal attack that leaves his arms ripped from a tree. The fear deepens as Dominique and Maxime are attacked near the car, forcing the group to regroup and rethink their plan. The boys sprint back to warn the girls, but the unidentified intruder cuts down the front porch swing, sending Samantha tumbling and vanishing into the basement. Alex and Jean pursue, determined to rescue, and they discover Pilou is dead. After a hard-won rescue of Samantha, a strange monster—camouflaged as a wall—knocks Alex unconscious and drags the trio into further peril.
Awakening, they find themselves bound and surrounded by people dressed as Matassalai, echoes from the Arthur trilogy that blur the line between fiction and fear. The Matassalai reveal a plan to send Alex into the Minimoy world, but Jean cuts the rope and fights back, while Renata creates a diversion to aid Alex’s escape and Samantha seeks a path for help. In a brutal twist, Renata is stabbed by a group of Minions, and Samantha is assaulted by a figure dressed as Maltazard. The violence could have triumphed, but a paranoid inhabitant of the house intervenes, firing at the attackers and forcing them to retreat. He orders Alex never to return, a stern boundary that underscores the harsh reality behind their fantasy.
As the police arrive, Alex, Samantha, and Jean are escorted to the infirmary, and the officer reveals the grim tally: the bodies of Alex’s friends have been found, with Mathilde dead in the barn from a bee allergy. The attackers are explained as drug-addicted teenagers who used to role-play games; three years earlier they staged a Batman vs. Superman game by jumping from buildings, and when they learned about the Arthur films they re-enacted them at the house on weekends, consuming drugs and letting the thrill eclipse humanity, with deadly consequences.
In the aftermath, the trio leaves in a police van for treatment, unaware of the unidentified observer watching from the house. The residence is soon sealed off, joined by medical examiners handling the bodies and the sober weight of tragedy that has rewritten their idea of an adventure. The line between play and danger has forever changed for Alex, Samantha, Jean, and the friends who shared a dream that turned into a harrowing night they will never forget.
