Beyond the Poseidon Adventure

“Before her fate is sealed by the deep, the superliner Poseidon will reveal one last secret.”

Captain Mike Turner (Michael Caine) wants the salvage rights to a capsized liner still floating bottom-up, and he boards it with his crew to claim her before anyone else can. Telly Savalas's Captain Stefan Svevo (Telly Savalas) has a rival party aboard too, and passengers are still trapped inside, waiting to be rescued. Irwin Allen puts all of them in the dark, upside-down hull together, each searching for a different cargo while the ship sits in the water.