A probe-like machine flies to the Earth. Without thought, it starts a forest fire. Gohan and Krillin put out the fire and save a purple dragon. The forest is gone so they gather the Dragonballs and Gohan wishes the forest back. The next day the machine scans the planet and reports back to a group of pirates. They talk for a little while and decide to plant the Tree of Might on the earth to drain all of its life energy. It quickly destroys a lot.

Gohan and Goku are at home relaxing. The purple dragon that Gohan saved follows him around. Chi-chi dislikes it, but Gohan keeps the dragon. Yamcha has bought in a new flying car and wants to impress Bulma with it. While flying the car is destroyed and Yamcha is left there.

The tree destroys cities and many miles of Earth. Goku, Krillin, Yamcha, Tienshinhan, and Chaozu all head to the roots of the tree. Chi-chi made Gohan stay home. They all try to blast the tree, but it's no good. The space pirates show up and start battling the Z fighters. Gohan sneaks out and finds the leader of the pirates who looks a lot like Goku. Taurus talks to Gohan and finds out he's a Saiya-jin. He then creates a fake moon like Vegeta did and turns Gohan Oozaru. Gohan goes crazy and starts attacking Goku. Gohan sees the purple dragon he saved and it gets his attention. Taurus then attacks Gohan so Goku cuts Gohan's tail off. The Z fighters are defeated so Taurus's henchmen attack Goku, but he kills them all. Taurus then attack Goku and they seem pretty close in power.

Taurus eats a piece of the fruit from the tree making him a lot stronger than Goku even when he does Kaio-ken x10. Goku makes a spirit bomb to try to defeat Taurus. Taurus sees the ball coming at him and deflects it. Taurus was able to deflect it since the Earth didn't have much power to give the bomb. Goku attempts another bomb, but this time he takes energy from the tree instead of the earth. He fires the bomb at Taurus and hits. Taurus is killed along with the Tree of Might and all the energy is give back to the earth. All is peaceful again on the earth.