A group of friends embarks on a yachting trip in the Atlantic Ocean, but their leisurely day turns nightmarish when a violent storm capsizes their boat. Struggling amidst the tumultuous sea, the survivors cling to the overturned hull, desperate for rescue. Out of nowhere, they spot an approaching ocean liner and, with their hopes lifted, they manage to board the eerily deserted ship. As they explore the massive vessel in search of help or any sign of life, a sense of unease begins to permeate the group, hinting that they are not alone and that the ship holds dark secrets.

The boat's lone remaining occupant, a young woman, comes to realize that there is something very wrong with the liner as she encounters increasingly bizarre and frightening events. She experiences a disorienting sense of déjà vu, as if she's lived these moments before, and starts to uncover unsettling clues that suggest the ship is caught in a sinister cycle. The disorienting reality mixed with violent confrontations with a mysterious masked assailant begins to fracture the group's sanity as they struggle to understand the labyrinthine puzzle they are trapped in and search for a way to break the cycle before they succumb to the ship's malevolent forces.