A talented warrior named Ikra joins Jack as he seeks a magical jewel that could send him back to his own time. However, Ikra’s true motives threaten to derail his quest.
After his lack of jumping skills cause him to lose a chance to return home, Jack helps a peaceful tribe of apelike creatures and their human leader defend themselves against the attacks of a larger rival tribe in return for lessons on how to “jump good”.
Centuries ago, the demon Aku is accidentally released by Jack’s father, who receives a magic sword from the gods. Eventually, he uses the same sword to imprison Aku beneath the earth.
Jack survives a series of traps and encounters a Viking king transformed into a giant rock figure by Aku, who insists that Jack slay him in battle so that he can reach Valhalla.
Five of the world’s greatest bounty hunters gather to compete for the chance to kill Jack. A sixth hunter, revealed to be the princess of a fallen kingdom, persuades the group to work together instead.
When Jack hears rumors of a time portal being found in the underwater city of Oceanus, Jack sets out to the city and is welcomed by its Triceraquins, but is unprepared for a terrible surprise.
