Unfortunately Frieza has survived Planet Namek’s destruction. He is found floating in the debris of Namek by his father, King Cold. Frieza is reassembled by his father’s minions. Frieza’s bent on revenge and eliminating all Saiyans. Because Saiyans are such powerful beings, they pose a great threat to him and his family, the strongest family on Earth.
All of the sudden, the people on Earth sense a strong evil power approaching. No, there are two strong powers approaching Earth; Frieza and King Cold arrive. Earth appears to have no defense against such a team. In despair, Earthlings ponders their fate.
From the future.
Suddenly a boy appears out of nowhere. The mysterious youth defeats all of King Cold’s henchmen with his sword. Vegeta wonders where this Super Saiyan came from, and is jealous of his strength. Frieza throws a fireball at the youth that is 10 times the size of the one that destroyed Namek. He catches and shatters the blast with little effort. To everyone’s amazement, both Frieza and King Cold are easily defeated by the teenager.
The mysterious stranger meets the gang from Earth and says he’s going to wait for Goku. He invites everyone to come with him. Sure enough, Goku shows up after a small wait.
The youth asks to talk to Goku alone, where he introduces himself as Trunks. He is the only surviving warrior from a battle that takes place in the future, when even Gohan perishes.
Trunks has come for two reasons: he wants to warn Goku that the androids that will arrive in three years and give Goku medicine for a heart condition that will take his life. Trunks explains that the androids were created by Dr. Gero of the Red Ribbon Army. He also reveals that Vegeta and Bulma are his parents, but tells Goku not to reveal this to them or he might not be born. Trunks leaves and says he will return in three years. The Z fighters start training in preparation and Teen Trunks returns to his own time.