Dragon Ball Z Episode 133: Nightmare Comes True
Episode 133 of 291 of Dragon Ball Z, aired March 25, 1992, 25 minutes. Available with English subtitles and dub where released.
Episode summary
Bulma arrives on the scene to discover that Android 20 is Dr. Gero himself. The insane scientist fires an energy blast that sends Bulma flying so he can activate Androids 17 and 18. After saving his young mother and younger self, Trunks follows Vegeta to stop him from facing the Androids head as the others find Gero's laboratory before he does, but will they make it?