The film is set in ancient China and follows the story of Monkey King Sun Wukong (Jet Li), who is imprisoned for 500 years for his mischievous behavior. He is freed by a young American adventurer named Ian (Michael Angarano), who stumbles upon the Monkey King's lair while searching for the fabled Elixir of Life. The Monkey King enlists Ian's help to retrieve a magical staff, leading them into a series of adventures filled with magic, martial arts, and danger.