Made by Genndy Tartakovsky, this cartoon tells the story of a great warrior displaced to the distant future by the evil shape-shifting wizard Aku. The world has become a bleak place under the rule of Aku, segregated into fantastic tribes and ruled by Aku's evil robot warlords. Jack travels this foreign landscape in search of a time portal that can return him to his home time so he can "undo the future that is Aku!".
Jack bumps into an old wizard who transforms him into a chicken - a rather goofy-looking master of the martial arts that nobody can understand. He gets captured and taken to a animal fight where he must defeat a robot beetle and snake. Jack wins but must then fight a spider-like creature, a giant worm, and the ratlike mechanical "Finisher". Jack's series of wins make his new owner a wealthy man but when he goes out to buy some decent clothing he bumps into the same wizard who hits them both with a spell - causing Jack to become human and the owner to become a chicken. Jack departs with a new found appreciation for the virtues of not eating chicken.
In his travels Jack comes to a tavern and a crying tavern owner. Then shadowy figures attack but Jack discovers they are teenagers, the "Children of Aku", under a magical musical spell. Knocking one out and following them in disguise, jack finds their rave and a sinister DJ playing the music. The DJ spots Jack and a fight ensues. Jack takes the fight directly to the DJ who is his near-equal. When Jack gets the upper hand the DJ dons a speaker-battlesuit but Jack regains his lost sword at the last minute and triumphs, freeing the children.
While taking a trip on a Old West-style train, Jack is stalked by a bounty hunter, Ezekial Clench. He manages to defeat him but unwittingly falls prey to Ezekial's ex-wife Josephine.
Aku resolves to do something about The Samurai once and for all and lures him into a cemetery.
As Jack travels towards Egypt, Aku unearths three ancient Minions and tasks them to kill Jack in return for freeing them.
To get to a time passage, Jack must pass a lake which sucks down any who try to cross it without touching its bottom.
Whilst crossing a desert to seek the Crystal of Cagliostoro, Jack comes across a oasis. He unwittingly disturbs an overly friendly creature, who begins following Jack, messing up Jack's every move along his quest.
Jack finds a swamp where a foul-tempered hermit answers his call. The wizard tells Jack of the titan Chronos and his powers over space and time, now locked within three pieces of armor set with gems.
Jack travels through a swampland, when he comes across a small shadow crying in the distance. After approaching the being, it drops a small toy doll and Jack follows it back to a small house in hopes of giving the item back to the creature.
Jack meets two Shaolin monks and after a brief fight he convinces them of his credentials and they take him to see their Grand Master at their hidden temple.
The gods Odin, Ra, and Rama battle a great dark evil. One shard escapes and falls to primitive Earth, creating a vast black forest. Down through the millennia it spreads and kills until the period of feudal Japan.
The gods send the Emperor a mystical horse to free him and deliver him to a castle in the sky. The three gods give him powers and forge a mystic sword for him to wield before sending him forth to fight Aku.
Jack is directed to a deathtrap-filled labyrinth which holds a diamond that can restore him to his time. Unfortunately a master thief also enters the labyrinth going for the item.