While the Android Saga literally brought Dragon Ball Z back down to Earth after the interplanetary action of the Frieza Saga, the series' inclinations toward harder science fiction themes and tropes remained stronger than ever. With time-travelers from a post-apocalyptic future and murderous androids, the Android Saga tied more into Goku's adventures in the original Dragon Ball series while pitting the Z Fighters against some of the most fierce and fearsome opponents they had ever known.
More than just bigger and more epic battles, the Android Saga also had some particularly effective plot twists and surprises that kept audiences on their toes just as much as it did Goku and his friends. Here are all the biggest twists and turns from the Android Saga.
Doctor Gero Is an Android All Along
The androids were described by Future Trunks as killer machines programmed by the villainous Doctor Gero to take revenge on Goku for destroying the Red Ribbon Army during the original Dragon Ball. This is further underscored by each of the androids bearing the Red Ribbon Army's insignia on their clothing. However, it is revealed that Android 20 is actually Gero himself.
While fighting against the Z Fighters, Gero's hat is knocked off, exposing his still intact and functional brain underneath. Gero reveals he transferred his brain into this robotic body to give himself the chance to fight Goku personally, with Frankenstein becoming his own monster.
The Wrong Androids
As Future Trunks recounted to the Z Fighters when he first arrived in the past from his alternate timeline, the androids from his time were merciless killers that easily murdered each of Earth's greatest defenders following Goku's death from a rare heart virus. After training for three years, Goku, Vegeta and Piccolo each showed themselves more than capable of handling the androids on their own.
However, when Future Trunks returns from his own timeline to help out the Z Fighters, he is shocked to discover that the initial duo of Androids 19 and 20 were not the enemies from his timeline he was speaking of at all. This suggests that Trunks' time travel altered the timeline before the more familiar Androids 17 and 18 were activated.
Goku Contracts the Heart Virus Anyway
Goku was never able to fight against Androids 17 and 18 in Future Trunks' divergent timeline, with Trunks revealing that he passed away some time before from a rare heart virus. Trunks gave Goku the medication that was unavailable to his timeline's Goku when he needed it most, presumably sparing Goku from the same untimely end.
However, Goku stopped taking the medication when the heart virus symptoms did not surface as Trunks predicted, resulting in the virus symptoms appearing in the middle of Goku's duel with Android 19. This nearly cost Goku his life, and he was incapacitated for the remainder of the Android Saga as he clung to life while taking the remainder of his medication.
Vegeta, Super Saiyan
All his life, Vegeta believed he was to become the first Super Saiyan in a millennium as part of his royal birthright and natural strength. Instead, Goku transformed into the first Super Saiyan while fighting Frieza on Namek, leaving a frustrated Vegeta in his wake when he was later resurrected. This frustration only grew when Future Trunks revealed himself as a Super Saiyan to defeat Frieza and his father King Cold.
However, Vegeta would eventually claim his intended destiny while training for the androids' arrival, shocking the other Z Fighters when he transformed into a Super Saiyan before their eyes to confront Android 19. In the resulting battle, Vegeta easily destroyed 19 before pursuing Gero into the wilderness, with Piccolo observing that Vegeta's newfound transformation may have exceeded Goku's in terms of raw power.
A Second Time Machine
While Future Trunks warned Goku and the Z Fighters of the androids three years in advance after traveling from his timeline, he was surprised how history was unfolding differently than he had expected. Left contemplating that tampering with time was having far-reaching repercussions, Future Trunks was in for one more nasty surprise at the very end of the Android Saga.
In a shocking twist, Future Trunks and the Bulma of the prime Dragon Ball timeline discover a time machine identical to the one Trunks used, but older and overgrown by moss, signaling that it had been there for years in secret. With a hatched egg nearby, the Z Fighters could only wonder what new evil had traveled back from the future to menace Earth.
