Dragon Ball Kai

The Pair Who Don't Leave a Trace! The Artificial Humans Appear (1x59)

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The Z Fighters (plus Bulma with a young Trunks) gather at the island in anticipation of the androids' attack. However, as the time approaches, Gohan reasons that due to being artificial humans, their enemies have no readable ki and can therefore only be found visually. The fighters then descend into the nearby city to search out their enemies. After a period of searching, Yamcha becomes the first victim of the androids, after being impaled and having his energy absorbed by Android #20. The others arrive just in time to save him, and Goku eventually persuades the androids to move to a new location to fight after a large portion of the city is destroyed.