The Thorntons are a British family living in Jamaica in 1870. When they decide to send their children back to England for a proper education, the long journey home quickly turns into pandemonium when a pirate ship, led by Capt. Chavez (Anthony Quinn), attacks their vessel. As the pirates begin to loot and pillage, the children mistake the pirate ship for their own. Now trapped on an unfriendly vessel, the children must figure out a way to reunite with their parents.