A luxury cruise liner sets sail across the Atlantic, filled with passengers celebrating New Year's Eve. Among them are a variety of characters: Mike Rogo, a former cop now working as the ship's head of security; Reverend Frank Scott, a clergyman with a crisis of faith; and Richard Clarke, an architect focused on his family's future and safety. As festivities ensue, a massive underwater earthquake triggers a colossal wave that capsizes the ship, flipping it upside down and causing chaos as passengers and crew members struggle to survive.

Trapped in the overturned vessel, a small group of survivors bands together, led by the determined Rogo and resourceful Scott. They navigate through the disorienting maze of the ship's interiors, facing deadly obstacles, rising water levels, and their own panic. Along the way, strained relationships are tested, and acts of heroism emerge. Each step upward toward the hull brings new dangers and the hope of rescue, but their fate remains uncertain as they push onward in their perilous journey to escape.