I'll Let You Live, On One Condition (A Dragon Ball Z Oneshot)

Age 764) It's been a year and a half since Goku and Frieza were thought to have died during their battle on Namek. Goku's friends and family attempted to resurrect him with the Dragon Balls only to learn that he had survived. Unfortunately for the people of Earth, so did Frieza. After being adrift in space among the scattered remains of Planet Namek, Frieza is found and rescued by his father King Cold. After undergoing intense reconstructive surgery, Frieza is stronger than ever and rapidly approaching Earth. The Z Warriors, sensing Frieza and another powerful evil energy drawing near quickly converge and prepare a plan of defense. As Frieza, his father, and a battalion of soldiers emerge from their ship, Gohan, Vegeta and the others embrace the possibility that they won't make it out of this battle alive. Just as all hope seems lost, Goku appears instantaneously using a new technique he learned on the planet "Yardrat" and quickly overpowers and kills Frieza and King Cold. After a nearly two-year conflict with the Saiyans and the Frieza-Force, Goku is ready to finally enjoy peace with his friends and family.

Age 766) After getting an urgent message from Piccolo, Gohan rushes to his home in East District 439 to find all his friends and family waiting for him, even Vegeta. Goku has fallen victim to a strange new illness with no known cure. Gohan runs to his father's side, but it's too late. After countless adventures culminating in the discovery and avenging of his fellow Saiyans, Goku is dead. Six Months Later, on an island nine miles off of South City, a mysterious duo appears and begins to wreak havoc. The remaining Z Warriors are quick to arrive and unfortunately just as quick to be slaughtered. Tenshinhan, Chiaotzu, Yamcha, Vegeta and Piccolo all fall victim to a deadly pair of androids, created by the Red Ribbon Army. As Piccolo falls, so does Kami, taking the Dragon Balls along with him. The only hope for the planet are Gohan, and Vegeta's infant son Trunks.