Batman asks Wildcat to help him take on an escaped prisoner. Wildcat isn’t impressed with the puny physique of their opponent and Batman pins the prisoner to a subway pillar with a batarang. The prisoner activates a chemical delivery system and pumps it into his body, and grows to incredible size. The escaped convict, Bane, easily smashes Wildcat away and goes after Batman. Batman tries to pull out the chemical tubes but Bane knocks him out and prepares to break his back. Wildcat recovers, grabs the batarang, and throws it, severing the tubes. The leaking chemicals touch the subway’s third rail, shocking Bane into unconscious.
Booster Gold, a museum guard from the 25th century who has stolen a battle suit and a time machine, has traveled to the 20th century to seek fame and fortune. However, toy company executives aren’t interested in his attempts to market himself and his toy car the Boostermobile, and suggest he get some name recognition before kicking him out of the building. Booster consults with his sidekick, a robot named Skeets that he brought back with him, and then decides he needs to do a team-up with an A-list hero.
Punch and Jewelee, two villains, rob a bank and try to escape but Batman easily brings them down. As the police take the villains into custody, Booster arrives and tries to convince Batman to take him on as his new partner. Batman refuses to work with a glory hound and quickly leaves while Booster gives his card to Punch and suggests they work as a hero/nemesis team.
Batman retires to the Batcave but Booster knows where it is thanks to his 25th century knowledge. Batman is busy investigating the theft of a meteorite from Greenland and realizes the thief is Kru’ll, an immortal caveman who gained his powers from the meteorite’s lutonic radiation at the dawn of time. Booster claims to know Kru’ll from the 25th century (he bumped into him at the museum when he was working as a guard). Skeets has a lutonic power cell and can track the meteorite’s energies so Batman reluctantly agrees to take them along.
Kru’ll is at a laboratory analyzing the meteorite and trying to activate its energies. The heroes arrive and Batman battles the villain. When Booster tries to help, Kru’ll grabs him and redirects his wrist blaster to take out Batman, Skeets, and finally Booster himself. Kru’ll ties up Batman and then fastens Booster and Skeets to a particle collider. As the caveman spends Booster on a one-way spin, Batman manages to free himself. In the collider, Skeets overloads the magnetic field holding them and break free just before the platform slams into the collider wall. When Booster boasts that Skeets runs on a lutonic battery, Kru’ll breaks a steam pipe, grabs Skeets, and disappears into the mist. An angry Booster is desperate to rescue his only friend, and Batman observes that now that he has something to fight for, he’s acting like an actual hero.
Kru’ll and his minions take Skeets to a museum. Kru’ll was a Cro-Magnon who gained immortality but all of his empires crumpled into dust. Now he plans to make his minions immortal so he has an army as long-lived as himself. To do so, Kru’ll uses the museum artifacts as a focus for Skeets’ energy. Meanwhile, Batman and Booster sneak into the building but Booster reacts when he sees his sidekick. They attack but Kru’ll and his minions quickly defeat them. Kru’ll traps them in a guillotine and releases the blade, but Booster manages to jam it with his Boostermobile. Batman escapes on his own and the two heroes fight the minions.
Kru’ll lets his minions delay the heroes while he releases the energy from the meteorite. The minions transform into super-powered cavemen and attack Booster. Batman goes after Kru’ll and manages to bring down a dinosaur skeleton on him. He then tells Skeets to release his entire energy charge. The resulting lutonic blast destroys the meteorite and transforms the minions back to normal. Booster frees Skeets, who says it knew Booster could do it all along.
As the police take Kru’ll away, Batman tries to point out that Booster has learned a valuable lesson about the nature of heroism. However, Booster is too busy setting up a deal with his agent. Kru’ll tells Booster that they’ll meet again and Kru’ll will prove victorious.
In the 25th century, a museum guard bumps into Kru’ll, who recognizes him from the past and starts to attack… Share this article with your friends