On New Year';s Eve, the luxury ocean liner Poseidon capsizes after being swamped by a rogue wave. Trapped beneath the waterline and implored by the captain to remain in place until a rescue team arrives, the panicked survivors struggle to keep their cool as the water begins to rush in, infernos blaze all around, and a loss of electricity plunges the doomed vessel into total darkness. The survivors are left to fight for their lives as they attempt to escape the sinking ship.