The Royal Star, the most exclusive cruise ship in the world, has just set sail from Miami on its inaugural voyage. For the hundred or so notable and well-heeled passengers, including Zack Chasteen, and his wife, Barbara, the itinerary is a secret and the week ahead promises to be an ultra-indulgent tropical sojourn.

But just an hour out of port, gunmen take over the Royal Star, killing most of the officers and sequestering passengers throughout the ship. Not only is Zack separated from Barbara, he has another worry —Barbara is eight months pregnant with their first child and could go into labor at any moment. As Zack and his fellow captives struggle to get an upper hand, the ship's hijackers offer few clues to their motives. Maybe it's a simple kidnap/extortion plot. Or maybe the hijackers are bent on more devious ends - using the Royal Star as a giant torpedo to blow up another cruise ship. Either way, Zack must figure out a way to stop them—while keeping himself and his wife alive.