One year after the catastrophic destruction of Planet Namek, the Z-Warriors are horrified to sense Frieza's immense energy signature approaching Earth, rebuilt as a cybernetic abomination alongside his powerful father, King Cold. Before the heroes can even formulate a desperate defense plan, a mysterious teenage swordsman appears out of nowhere, effortlessly transforms into a Super Saiyan, and slices Frieza to pieces. The youth, named Trunks, privately reveals to Goku that he has traveled back in time from a post-apocalyptic future. He warns Goku that in exactly three years, two lethal, cold-blooded Androids created by the rogue Dr. Gero will emerge to slaughter the Z-Warriors, and that Goku will tragically die of a rare heart virus unless he takes a special medicine.