Karen Harrison is a spoiled, rich, American predator who falls head-over-heels for the brooding, tormented, about-to-retire matador, Luis Santos who has inexplicably run away prior to a corrida that was to occasion the "alternativa" of a young, up-and-coming bullfighter.

A group of communist spies plan to blow up an essential commercial artery, the Panama Canal. To this end, they have kidnapped a nuclear scientist and are traveling by steamship to the coast of South America. Luckily for western civilization, the hard-nosed ship's captain, played by Barton MacLane, has other ideas.