Booster Gold is a time travelling super hero from the future who looks up to Batman. Somehow, he became a member of the Justice League and Batman tried to teach him what it took to be a true hero. Weekly sparring sessions were held in the Hall of Justice's training area. Each session was very short as Batman knocked him out with one punch usually. One night, Uthool possessed Batman and went to the Hall where he planned to overload the power core, causing an explosion to restore Earth's primitive glory. Booster Gold, unaware of the possession, grabbed Batman and pulled him into the training area for their sparring session. Uthool was fixated on getting to the power core and tried to leave the boxing ring. To Booster's surprise, he flipped Batman. Batman pounded him mercilessly. During Superman and Uthool's fight, Booster awoke. Something was bothering him so he accessed his files and rewatched sparring sessions from 30, 18, and 8 days ago. In all of them, Batman took him out with one hit.
Wonder Woman, still tied up in her Lasso of Truth, told him this time it took Batman more than a punch to win. Booster finally noticed Wonder Woman. She heavily suggested he untie her so she could pulverize the fake Batman. Booster was buried under rubble after the Hall collapsed due. He emerged last, still oblivious of what happened. He wondered who broke the Hall but quickly followed up where they were going to sleep. He proposed the Batcave.