After a pair of models go missing from a boat, a rescue party discover an empty galleon carrying the coffins of the long dead Knights Templar. The rescue party board the galleon and then discover their own boat has vanished. The survivors struggle to fight off the spectral knights with what little knowledge they have of them.

Laurent van Horn is the leader of a band of Dutch refugees on a ship seeking freedom in the Carolinas, when the ship is wrecked on the coast of Cartagene, governed by Don Juan Alvardo, a Spanish ruler. Alvarado has Laurent thrown in prison, but the latter escapes, and five-years later is a pirate leader. He poses as the navigator on a ship in which Contessa Francesca, daughter of a Mexican noble, is traveling on her way to marry Alvarado, whom she has never seen. Laurent's pirates capture the ship and Francesca, in order to save another ship, gives her hand-in-marriage to Laurent, who sails her to the pirate hideout. This irks his jealous pirate comrades Anne Bonney and Captain Benjamin Black. They overpower Laurent and send Francesca to Alvarado, and then Mario du Billar, a trusted right-hand man, makes a deal to deliver Laurent to Alvarado.

A scuba team, a marine archaeologist and a Mexican historian join forces to reach the wreck of an historic Spanish galleon before a well-armed commercial expedition does.