The two Gokus engage in a Kamehameha clash, but their blasts cancel each other out. During the fight, Goku discovers that there is an invisible barrier around the Prison Planet that prevents them from escaping. This Goku, referred to as 'Xeno Goku', sees Fu and assumes that the trio are working for him he immediately transforms into Super Saiyan 4 and attacks Goku, who reacts by transforming into Super Saiyan Blue.
The trio arrive on the planet and meet an alternate version of Goku, who is revealed to be part of a group called the Time Patrol. A mysterious figure emerges, introducing himself as Fu he tells Goku, Vegeta and Mai that Future Trunks is trapped on a world called the 'Prison Planet', a planet where warriors from alternate timelines and dimensions fight as part of an experiment conducted by Fu. Goku and Vegeta's training with Whis and Beerus is interrupted by the arrival of Future Mai, who tells them that Future Trunks has been captured. Goku! A Transcendent Battle Begins on the Prison Planet!' ( 悟 ご 空 くうvs 悟 ご 空 くう！ 監 かん 獄 ごく 惑 わく 星 せいで 超 ちょう 絶 ぜつバトル 開 かい 幕 まく！, Gokū vs Gokū! Kangoku Wakusei de Chōzetsu Batoru Kaimaku! ) Episode listing Universe Mission Prison Planet Saga
