Cuban-born Mercedes Spivey and her American husband, Nolan, win a five-day cruise to Cuba. Although the circumstances surrounding the prize seem a little suspicious to Mercedes, Nolan's current unemployment and their need to spice up their marriage make the decision a no-brainer. Once aboard, Mercedes is surprised to see two people she met through her ex-boyfriend Lorenzo: former University of Havana professor Selfa Segarra and down-on-his-luck Spanish writer Javier Jurado. Even stranger: they also received a free cruise.

When Selfa disappears on their first day at sea, Mercedes and Javier begin to wonder if their presence on the cruise is more than coincidence. Mercedes confides her worries to her husband, but he convinces her that it's all in her head.

However, when Javier dies under mysterious circumstances after disembarking in Havana, and Nolan is nowhere to be found, Mercedes scrambles through the city looking for him, fearing her suspicions were correct all along.