A new faction of the
Jokerz gang—consisting of Bonk, Woof, Ghoul, Chucko, and the Dee-Dee twins—attempts to steal high-tech electronic equipment but is intercepted by Batman (
Terry McGinnis), protégé of the original Batman,
Bruce Wayne. The gang reports back to their leader, revealed to be the
Joker, Bruce's arch-nemesis, who has been presumed dead for
four decades. The Joker kills Bonk for his defiance and to intimidate the other members. Later, the Jokerz attack a
press conference commemorating Bruce's return to
Wayne Enterprises, and the Joker reveals himself to Bruce, who insists that he died. After fending off the attack, Terry demands information from Bruce and Police Commissioner
Barbara Gordon, the former
Batgirl, but neither gives him the answers he seeks. Not wanting Terry to face the Joker, Bruce orders him to return the
Batsuit. Terry argues that being Batman is what makes him a worthwhile person, but Bruce rebukes him, comparing him to his former sidekicks. Later, the Jokerz attack Terry, nearly killing his girlfriend,
Dana Tan, while in the Batcave, the Joker poisons Bruce and his
Great Dane,
Ace, revealing that he knows their secrets. After Terry saves Bruce's life with an antidote, Barbara finally explains the Joker's disappearance: After
Nightwing (
Dick Grayson) had left Gotham City for
Blüdhaven, the Joker and
Harley Quinn kidnapped
Tim Drake, then
Robin, while he was on patrol, torturing and brainwashing him for three weeks at the abandoned
Arkham Asylum, learning Batman's secret identity, and turning him into a teenage facsimile of the Joker, scheming for Robin to kill Batman. After Batman and Batgirl found Tim, a battle ensued, during which Tim briefly came to his senses and killed the Joker instead, while Harley fell down a ravine and was presumed dead. They buried the Joker underneath the asylum, and only Barbara's father and predecessor
James Gordon knew of this incident. Over the next year, Tim recovered with help from Bruce's family friend
Leslie Thompkins, was forced to retire from superheroics, and severed ties with Bruce, leaving to make it on his own. As Batman, Terry visits Tim, now a successful telecommunications engineer with a family, who voices bitterness towards his past but denies involvement in the Joker's return. Terry's next suspect is Jordan Pryce, a Wayne Enterprises executive who hates Bruce for ruining his chance to take over the company. He ultimately finds that Pryce is not the Joker but had conspired with him to kill Bruce. When a
directed-energy weapon strikes Pryce's yacht, Terry rescues him before turning him over to the police. In the Batcave, after realizing the Joker only destroyed the Robin costume, Terry recalls Tim's grudge against his old persona and deduces he must be involved. Cross-referencing Tim's expertise as an engineer with the Jokerz' thefts, Terry and Bruce discover that their stolen equipment can create a jamming system that seizes control of a laser-armed
military satellite. When Terry goes to face Tim in his workplace, he triggers a trap set by the Joker, whom he follows to an abandoned candy factory. Subduing the Jokerz with Ace's help, Terry confronts Tim, who subdues Terry by disabling his Batsuit and then transforms into the Joker as Bruce watches in horror from the Batcave through Terry's Batsuit. The Joker explains that he encoded himself into a
DNA microarray, implanted and hidden behind Tim's ear, allowing him to survive death by taking over Tim's body and intending to do so permanently. With the satellite, the Joker plans to kill Bruce and Terry's loved ones before destroying Gotham City. As they battle, Terry uses one of the Joker's electric joy buzzers to destroy the biochip and with it the Joker's persona forever. Terry and Ace escape with the unconscious Tim as the satellite destroys the Joker's lair, then shuts down. Following the Jokerz' arrests, Barbara hides Tim's unwitting involvement to protect him while the Joker is declared dead. The Dee-Dee twins are bailed out of jail by their grandmother, an elderly and reformed Harley Quinn who survived the fall. Bruce makes amends with Tim and Barbara while Tim recovers in the hospital, during which he tells Terry that he was wrong: it isn't Batman that makes Terry worthwhile, it's the other way around. == Voice cast ==