Willa Sullivan, a 31-year-old freelance marketing professional, is struggling to rebuild her life after ending her eight-year relationship with Ravi, her former fiancé. She called off their wedding three weeks before the date, convinced they had grown apart over differing desires about children, lifestyle, and communication. Now alone in a studio apartment in Jersey City, she spends her evenings binge-watching horror movies on the recommendation of her best friend Cassie, swiping through dating apps, and crying into a whiskey sour at a neighborhood bar.
Willa drives to the Hudson Valley for the wedding of her college friends Steph and Jason at the Lakeside at Wild Heart Acres, a former summer camp converted into a venue with cabins, a reception hall, and a lake. She reunites with Evan, her sharp-tongued best friend; Wyatt, Evan's gentle husband; Cassie; and Cassie's easygoing husband, Luke. Willa learns that Ravi has brought a date named Tanya, and the news blindsides her since no one warned her in advance. When she sees Ravi and Tanya together near the ceremony area, she panics and flees into the woods.
Hyperventilating against a tree, Willa experiences strange sensory distortions: The ground feels soft beneath her, and she has a sensation of falling. Through the trees, she glimpses a towering figure in all black, wearing a balaclava with duct tape over the mouth and fake eyeballs adhered to the mask. The figure waves. Danny, Jason's charming childhood best friend, startles her from behind, and when she turns back, the figure is gone. She dismisses the sighting as a stress-induced hallucination and returns to the ceremony with Danny, with whom she feels an immediate chemistry.
The ceremony proceeds at sunset. Afterward, Danny and Willa slip away and share an intense first kiss at her cabin. Walking back, they discover a smear of blood on one of the cabins, disturbed grass, and a plastic eyeball on the ground. A scream tears through the night. They find Steph in a nearby cabin, her eyes gouged out, bleeding from a stomach wound. Willa holds her as she dies. Behind them in the dark stands the masked figure, now nearly seven feet tall, his balaclava covered in multiplying real eyes, a bloody bowie knife in hand.
What follows is a massacre. The killer, whom Willa mentally names the Eyeball Man, murders guests across the venue, throwing a knife into Wyatt's skull and setting the reception hall on fire. Evan refuses to leave Wyatt's body. Willa charges the Eyeball Man with a kitchen knife but is caught by the throat. He whispers, "I see you," then drives his blade between her eyes. She dies.
Willa wakes in her apartment on Friday morning, the same Friday. She calls Cassie in a panic, describing her vivid "nightmare." Cassie chalks it up to stress and horror movies. Willa drives to the venue experiencing overpowering déjà vu: the same outfits, the same conversations, the same cabin. Every detail matches, down to the polka dots on Evan's bow tie. Steph confirms that Tanya exists, destroying Willa's hope that the first day was only a dream.
This second loop ends differently but no less violently. A gothic phantom in a black top hat, his eyes glowing red and his mouth full of raven beaks instead of teeth, commands hundreds of ravens that swarm the reception. A raven slashes Danny's hand, and a black, feathery infection rapidly consumes his body. The phantom lifts Danny into the air and inhales his soul before turning on Willa. He wraps a tendril of fog around her neck and extracts her soul. She dies again.
The third loop brings zombies. A rabid deer charges the ceremony, and the infection spreads through the guests. Willa and Ravi barricade themselves in her cabin and, for the first time, confront each other honestly. Willa demands he acknowledge she was right to end things; Ravi asks for more time. Police arrive but fire indiscriminately, killing Ravi, who is not infected. Willa is shot as well.
Exhausted and desperate, Willa decides in the fourth loop to skip the wedding, reasoning that her presence might be the trigger. She stays home, orders takeout, and watches movies. It makes no difference. The sky turns a noxious green, and an enormous alien entity seizes Willa in a beam of light. Trapped in its grip, she feels an overwhelming longing for her life and the people in it. She begs it to let her go. It responds with a single telepathic word: "Okay," and drops her. She falls and dies.
The fifth loop proves pivotal. Willa returns to the wedding resolving to be present and emotionally honest rather than guarded. She tells Evan she is not okay. She tells Cassie she is proud of her. At the reception, Ravi mentions that Tanya, a physics teacher, once experienced something like a time loop at this venue when it was still a summer camp. Willa pulls Tanya aside. Tanya explains the phenomenon as a traversable wormhole in the woods, a closed timelike curve that bends the day back to its starting point, shaped by the trapped person's subconscious. She tells Willa to retrace her steps from the first day and find the wormhole's entrance, warning that it could collapse, erasing Willa from existence. Before Willa can act, sentient flower sprites burst from the wedding arrangements, drag her into the lake, and drown her.
The sixth loop is the shortest. Willa leaves early to search the woods but never arrives. An earthquake strikes, and a colossal Godzilla-like creature rises from the bay, incinerating her with its fire breath.
On the seventh morning, Willa wakes laughing. She resolves that this will be the last time. She drives to the venue, follows the familiar script of reunions and group photos, and finally breaks away into the woods, retracing the path she took on the first day when she fled from Ravi and Tanya. The ground grows unstable. Her vision warps. She feels the sensation of falling, signs she is nearing the wormhole.
The Grim Reaper appears: a robed skeleton wielding a scythe, its skull crawling with worms. It stands between Willa and the wormhole, which shimmers faintly in the air. Willa throws a rock into the Reaper's eye socket and lunges for the fallen scythe. In a moment of clarity, she recognizes that the true terror is not death but the unknown future, her life beyond the loop. She releases the scythe. She lets go. The Reaper falls backward into the wormhole, which collapses in a final flash of light.
Willa comes to on her back in the woods. Danny finds her and introduces himself for what is, to him, the first time. She races to the ceremony, arriving barely on time, under-dressed and dirt-streaked. She sits through the vows and truly listens. She approaches Ravi and Tanya at the cocktail hour, introduces herself graciously, and shares a brief, cordial exchange with her ex. The wedding unfolds without incident: toasts, dinner, dancing until midnight. No masked killers, no ravens, no zombies, no aliens, no flower sprites, no kaiju, no reaper.
Alone by the lake after the reception, Willa discards her cigarettes. Danny finds her, and they share a warm but unburdened moment. She reflects that her story is neither a love story nor a horror story. It is hers, and it can be whatever she makes it. She turns from the water, looks ahead, and moves forward.