Over 2,000 passengers and crew are celebrating New Year's Eve aboard the luxury cruise ship 'Poseidon' on the open sea. Without warning, at midnight, a rogue wave hundreds of feet high, slams into the ship and rolls it upside down. Most of the passengers and crew are killed outright, but several hundred remain alive in the ballroom, where the party was being held. Realizing their only hope of rescue lies at the surface of the water, a handful of survivors,...

After a plane crash, Claire, a young therapist, is assigned by her mentor to counsel the flight's five survivors. They share their recollections of the incident. Some say there was an explosion, but the airline claims it never happened. Claire becomes intrigued by Eric, the most secretive of the passengers. Despite her better judgment, Claire's professional relationship with Eric blossoms into a romance. Then the survivors begin to disappear mysteriously,...