A few years prior, the tyrant Frieza destroyed the Planet Namek during his battle with the newly transformed Super Saiyan Goku. The peaceful Namekians found themselves without a home for months. Eventually they had a new planet created for them with the help of the Dragon Balls. For three years or so they lived in peace on their new planet. One day however, a strange metal planet began to absorb New Namek. The silver planet wrapped around New Namek, absorbing its energy. Dende, who is now the Earth’s guardian, senses the plight of his people and calls Goku to ask for help.
Goku, Gohan, Krillin, Piccolo, Oolong, Yajirobe and Master Roshi arrive and encounter an army of strange, large, silent robots. We learn that Cooler, Frieza’s older brother, that Goku was thought to have killed a few years earlier, is the one who deployed the robots on the planet to enslave the Namekians, whom he plans to use as biological fuel for the Big Gete Star. Goku then fights Cooler, while the other Z-Fighters battle Cooler’s robots.
At first the Z-Warriors have trouble penetrating the robots’ armor, but Piccolo instructs them to concentrate their energy to one point, and doing so allows them to destroy a few of the robots. However, there are far too many to handle and all the warriors, except Piccolo, are captured along with a village of Namekians. Piccolo is left behind, and destroys all the robots. He then makes his way to rescue those who were captured. Throughout the battle, Goku is distracted by a familiar face – that of Cooler, who he was sure had perished years ago. Goku battles Cooler, but it is apparent that Goku is no match for Cooler’s new metallic form which gives him the ability to regenerate himself. Cooler also reveals his ability to use the Instantaneous Movement technique, which Goku also uses. Goku continues to struggle even after becoming a Super Saiyan. Cooler reveals that the Big Gete Star constantly monitors his body, and fixes any flaws that may occur, in this case Cooler’s arm being torn off by Goku.
Just before Goku is choked to death by Cooler, Vegeta, who had arrived in a separate pod, shows up just in time to help Goku. The two Super Saiyans attack Cooler and they soon are able to kill him. However, the Big Gete Star once again corrects a flaw in Cooler’s design. In this case the flaw was having only one body. So, the computer gave Cooler one-thousand bodies. Outnumbered and exhausted, Goku and Vegeta are captured and transported to the Big Gete Star’s core to be used as energy. As Cooler is leeching their Saiyan strength via strange wires, Goku and Vegeta regain consciousness and release all their Super Saiyan energy to the wires, overloading the system. They then blast the true Cooler with the last of their energy, causing his ultimate demise. Meanwhile, Piccolo arrives in the Big Gete Star, and meets up with a clone of Cooler, which explodes. Eventually, all the other clones of Cooler, and every other robot, in the Big Gete Star explode. Piccolo and the rest escape before the Big Gete Star explodes in New Namek’s orbit.
Goku and Vegeta fall from the sky near the rest of the Z-Fighters, and everyone rejoices. They then realize that Vegeta is nowhere to be found, reasoning that he never was fond of happy endings, to which Goku looks up at the sky and concludes that if not for him, there never would be one. Vegeta is shown flying in space in his spacepod with the last remaining chip of the Big Gete Star in his hands. He then crushes it, ensuring that it will never create another monstrosity like the Big Gete Star ever again.