A cruise ship succumbs to a terrorist act and capsizes on New Year's eve. A rag-tag group of survivors, spearheaded by a priest and a homeland security agent, must journey through the upside down vessel and attempt an escape.

Charlie Mason and Rusty Fleming are star reporters on a Chicago tabloid who are romantically involved as well. Although skilled in ferreting out great stories, they often behave in an unprofessional and immature manner. After their shenanigans cause their frustrated city editor to resign, the publisher promotes Charlie to the job, a decision based on the premise that only a slacker would be able crack down on other shirkers and underachievers. His pomposity soon alienates most of his co-workers and causes Rusty to move to New York. Charlie resigns and along with gangster friend Smiles Benson tries to win Rusty back before she marries a stuffy society author.

A passenger ship, on her way to the scrap yard is pushed to her limits by the new owners to save on the dismantling fees. A tidal wave hits her, flipping her over so that all the internal rooms are upside down. A priest takes a mixed band of survivors on a journey through the bowels of the ship in an attempt to survive.

It is New Year's Eve, and over 2,000 passengers & crew are ringing in the New Year aboard the huge cruise ship 'Poseidon' when it capsizes on the open sea in the middle of the North Atlantic Ocean! A small group of survivors find themselves unlikely allies in a battle for their lives. Preferring to test the odds alone, career gambler Dylan Johns ignores captain's orders to wait below for possible rescue and sets out to find his own way to safety. What begins as a solo mission soon draws others, as Dylan is followed by a desperate father searching for his daughter and her fiancée--a young couple who hours before couldn't summon the courage to tell him they were engaged and now face much graver challenges. Along the way they are joined by a single mother and her wise-beyond-his-years son, an anxious stowaway and a despondent fellow passenger who boarded the ship not sure he wanted to live but now knows he doesn't want to die...