Goku and the others arrive at the site of a buried spaceship and watch as Spopovitch and Yamu deliver Gohan's energy to the evil wizard Babidi and his partner, Dabura.
After Goku defeats Yakon, Dabura prepares to fight the Saiyans himself. Meanwhile, a battle royal is held between the remaining contestants of the tournament.
Goku learns of Vegeta's sacrifice, which ultimately failed to defeat Majin Buu. Meanwhile, a weakened Supreme Kai searches for Gohan, whose fate is still unknown.
Supreme Kai reveals his plan to teach Gohan the art of mastering the legendary Z-Sword in order to defeat Majin Buu. Meanwhile, Goku teaches the fusion technique to Goten and Trunks.
As Majin Buu lays waste to another city, Goten and Trunks contact Babidi and inform him that they will soon be strong enough to fight Buu. They continue their fusion training.
Babidi and Majin Buu plan to destroy West City, however Goku confronts them, hoping to buy some time. Meanwhile, Trunks is on a mission to retrieve the Dragon Radar from West City, which will be destroyed if Buu gets there first.
Due to his energy being drained from transforming into a Super Saiyan 3, Goku does not have much time left on Earth. He wastes no time, teaching Goten and Trunks the final key component to mastering the fusion technique.
Finally mastering the Fusion Dance, Gotenks goes out on a search for Majin Buu, despite Piccolo's protest. Meanwhile, Old Kai reveals he has the ability to unlock a warrior's true potential.