Dr. Raichii is believed to be the sole survivor of the Tsufurujin, a species wiped out by the Saiyajin centuries ago. He now seeks vengeance against the lone living Saiyajin, Goku and Vegeta. Employing devices that release destron—a lethal gas capable of annihilating all life on Earth—he threatens the planet. The Z fighters have just 72 hours to locate and eliminate Dr. Raichii.