Brains and Brawn (悟飯とベジータのドラゴンボール, Gohan to Bejīta no Doragon Bōru; lit. "Gohan and Vegeta's Dragon Ball") is the two hundred sixty-ninth chapter of the Dragon Ball manga. This chapter's anime counterpart is the episode "Unknown Enemies".
The chapter opens with Krillin and Bulma standing near their cave after Vegeta leaves with their Dragon Ball. Bulma complains that it is all over now that Vegeta has it, but Krillin tells her that it should be okay anyways, as the ball that Gohan is after was really hidden by Vegeta, so Vegeta will not have all seven. Gohan is then seen flying back to the cave with the Four-Star Ball when he senses a powerful ki, which he identifies as Vegeta. Vegeta senses Gohan as well, though Gohan quickly suppresses his ki and hides behind a rock.
Vegeta, knowing that someone is nearby, threatens aloud to destroy the entire area. Gohan puts down the Dragon Ball and emerges to confront Vegeta. Vegeta tells Gohan that he took his Dragon Ball from Krillin, and asks Gohan what the Dragon Radar is. Gohan tells him that it is simply a watch, and Vegeta mocks Earthlings for not having the technology to create a smaller one. After asking whether Goku is on Namek, Vegeta knees Gohan in the chest and flies off. Though hurt, Gohan still manages to bring the Dragon Ball back to Krillin and Bulma, who decide that they must quickly leave their cave.
Meanwhile, Vegeta has gone to look underwater for the ball that he hid (which Gohan took). When he is unable to find it, he quickly realizes that it was Gohan's doing and that the Dragon Radar is not simply a watch. Enraged, he flies back to the cave, but finds it deserted. Gohan, Krillin, and Bulma have hidden inside a chasm on another island. Bulma complains about their living conditions, and Krillin states his intent to take Gohan to Grand Elder Guru's house.