Captain “Lucky Jack” Aubrey (Russell Crowe) of the HMS Surprise receives orders to sink or capture the French privateer Acheron off the east coast of South America. In his first encounter with the enemy vessel, the more powerfully built French warship gets the better of his crew and nearly sinks the Surprise. Dr. Stephen Maturin (Paul Bettany), Aubrey's best friend and ship's surgeon, tries to convince him there is no shame in returning home given the conditions they face. Torn between duty and friendship, the fate of his crew weighs on his mind.

Struck by lightning, a Defense Department robot malfunctions and, as a result, develops its own consciousness. Escaping the military, it finds refuge with a young woman (Ally Sheedy) who helps hide "Number 5" from its inventor, Newton Crosby (Steve Guttenberg), and the government who wants its weapon back.

Remember, remember the 5th of November. The significance of this date in England goes back to 1605, when a Catholic terrorist by the name of Guy Fawkes tried to blow up Parliament in protest over how Catholics were treated. Fast forward to the near future and meet V (Hugo Weaving), our tragic hero, who struts around town wearing a Guy Fawkes mask and is a terrorist in his own right—or at least the totalitarian government has labeled him as such.

With his great grandfather implicated in the assassination of Abraham Lincoln, treasure hunter Benjamin Franklin Gates (Nicolas Cage) enlists the help of his acrimoniously divorced parents (Jon Voight and Helen Mirren) to search out clues to clear the family name. From Buckingham Palace to Mount Rushmore, Gates pursues the Book of Secrets, but he must find a way to speak to the one man who has access to it, the President of the United States.