The film's cold opening replays the death of Dr. Gero at the hands of the Androids 17 and 18, and also revealing that Gero is still around in the form of an underground computer, still working on three new Androids.
The real film now opens with the completion of Androids 14 and 15, who attack Goku while he is shopping with Chi-Chi and Gohan. Not wanting to destroy the city they're in, Goku and Trunks leave for an uninhabited Arctic area. The fight seems even until Android 13 shows up - at least until Vegeta and Piccolo arrive. At that point of time, both Goku, Vegeta, and Trunks ascend to their Super Saiyan forms and 14 and 15 are destroyed by Trunks and Vegeta, respectively. Just when the fight seems won, 13 shows off his "Super" form by absorbing two components of the two fallen androids, vastly transforming into a blue behemoth and increasing his power, changing the battle's outcome yet again. But then Goku prepares his Spirit Bomb, and, after transforming into a Super Saiyan, he absorbs its energy into his body and destroys the Android menace. As 13, 14, and 15 are ultimately destroyed, Dr. Gero's computer shuts down for good, while still shouting the words "Goku must die!".
Later, Goku and his friends are healing in the hospital, but Piccolo and Vegeta are sharing a private moment of "hatred" by sitting back-to-back on a small rock in the sea. Piccolo asks "Is it over?", to which Vegeta replies in an annoyed tone, "Not until the fish jumps!". A fish jumps out of the water and Vegeta says, "It's over.