Offseason

Marie Aldrich receives an urgent letter from cemetery caretaker Haskell Grierson, summoning her to Lone Palm Beach. Concerned about her mother's desecrated grave, she is accompanied by her estranged boyfriend George Darrow.

Upon reaching the island, the couple meets the 'Bridge Man' who warns them that tourist access will close until Spring. They must return to the mainland before the bridge goes up for the night, adding urgency to their quest.

George leaves Marie alone in the cemetery to search for Grierson. During this time, she encounters Miss Emily, an enigmatic older woman, and has a strange experience in a foggy forest filled with entranced figures.

Marie and George stop at a restaurant to ask about Grierson, but the locals act strangely. A fisherman hints at knowing about Marie's mother but is interrupted by suspicious locals, deepening their unease.

Marie confides in George her suspicions regarding her mother's will and recounts a chilling tale her mother told her about the island's settlers making a pact with a sea demon. Ignoring her concerns, George dismisses the possibility that there is any truth to the supernatural tale.

As they attempt to return to the bridge, fallen trees obstruct their path. In the chaos of navigating around them, George crashes the car, leaving them stranded in the darkness of the island.

Marie awakens in the crashed car to find George missing and the bridge raised, effectively trapping her on the island. She begins to search for him, but is dismayed to find the town deserted and eerie.

In her search, Marie experiences unsettling flashbacks, including arguments with her mother about the island’s dark history. The ghostly memories add layers to her understanding of her family's past.

Marie visits the flower shop where she finds a scrapbook containing newspaper clippings about her mother. Here, she encounters Miss Emily again, but the old woman appears entranced, as if under a spell.

Marie runs into the fisherman again, who reveals the dark truth that the islanders are cursed and that her mother had returned due to debts owed to the sea demon. He shares that each year, only one resident stays awake to witness the horror.

As they retrieve his boat, the fisherman vanishes, leaving Marie alone with the growing threat. She hears George's voice through the radio and vows to find him just as she witnesses the fisherman being devoured by dark creatures.

Upon escaping to the raised bridge, Marie is confronted by a blood-covered George, who reveals signs of possession. In a moment of desperation, fearing for her life, Marie shoots George when he approaches her menacingly.

The Bridge Man intervenes, gun drawn, and reveals that Marie’s mother was deeply troubled and had committed terrible acts. He insists that Marie must witness the consequences of her family's actions on the island.

Back at the cemetery, Marie is faced with the resurrected form of her mother, Ava. As a massive creature appears from the sea, Marie screams her apologies while watching her mother being dragged into the depths.

In the epilogue, a couple prepares to leave Lone Palm Beach at the end of the tourist season. Marie, now the new proprietor of the flower shop, warns them about the dangers of staying past the bridge's closure, revealing her deep connection to the island.