After doing time for two decades, infamous pirate Yellowbeard (Graham Chapman) breaks out of prison determined to recover the treasure he buried so long ago. Trouble is, the map has been tattooed onto the head of his effete son, Dan (Martin Hewitt), who has little appetite for plundering the high seas. Even worse, a number of rivals aim to beat Yellowbeard to his fortune, including an old shipmate (Peter Boyle), a secret agent (Eric Idle) and a pair of conquistadors (Cheech Marin, Tommy Chong).