This animated feature opens with Barbara Gordon, also known as Batgirl, voiced by Tara Strong, as she watches Bruce Wayne, or Batman, portrayed by Kevin Conroy, meeting with Commissioner Jim Gordon, voiced by Ray Wise. The tension escalates when Gordon shines the bat-signal to summon Batman for a robbery in progress. Batman rushes off into action, while Batgirl boldly decides to chase the robbers on her own.

The criminals are escaping in a getaway van, driven by two punks, one of whom is Paris Franz, voiced by Maury Sterling, the nephew of Gotham City’s notorious crime boss Carlos Francesco, voiced by John DiMaggio. Engaged in a thrilling pursuit, Batman hunts the crooks in the Batmobile while Batgirl leaps onto the van. An explosive confrontation occurs when Batgirl blows open the backdoor, allowing some of the criminals to shoot at Batman. Paris retaliates and shoots at Batgirl, resulting in her falling off the van. Ultimately, they manage to capture one criminal, but Batman expresses his frustration towards Batgirl for her reckless actions.

Meanwhile, Paris meets with Francesco, who is furious with his nephew for Batgirl’s interference, which led to four of his men being captured along with a loss of $100,000. Francesco threatens Paris, demanding that he retrieve the money or face deadly consequences. Paris, intent on proving himself, and his gang then plot to rob a warehouse. Batgirl, determined to prove her worth, tracks them down. Paris, having developed a dangerous obsession with her, uses knockout gas on her, but she manages to strike him before hiding in a vault as the gang escapes. After regaining consciousness and amidst police chaos, Batgirl meets Batman on a rooftop, where their discussion reveals her anger and feelings of mistrust toward his protective stance.

Following a harrowing night, the criminals gather on their boat after indulging in activities with prostitutes. Paris receives a call from Francesco, resulting in the shooting of one of his associates. As Paris and his remaining cohort attempt to evade four gunmen on a motorboat, they cunningly rig their own boat to explode, eliminating their attackers.

In a twist, Paris sends a video message to Batgirl, designed to lure her into a trap. Despite Batman’s warnings to stay away from the case, Batgirl follows the breadcrumbs he left, leading her to a disturbing scene where she discovers Francesco’s corpse. Forced to escape from two of Francesco’s men, she is saved just in time by Batman, reigniting their tensions.

On a rooftop, amidst an intense argument, Batgirl impulsively kisses Batman, leading to a moment of vulnerability where she removes her cowl and suit, revealing her full self. Their ensuing passionate encounter becomes a source of deep regret for Barbara.

The night unfolds with Batgirl alerting Batman about Paris, who orchestrates chaos with an RPG hitting the Batmobile. As Batman makes a daring jump to safety, Batgirl arrives on her motorcycle, confronting Paris fiercely but hesitating before crossing a lethal line.

Once Paris is apprehended, Batgirl realizes the wisdom of Batman’s earlier concerns for her safety. In a move to redefine her path, she meets with him as Barbara, announcing her decision to hang up her Batgirl persona.

Time passes, and Batman is seen at a crime scene with Detective Harvey Bullock, voiced by Robin Atkin Downes, discovering four deceased men bearing grotesque smiles—an unmistakable mark of the infamous Joker, voiced by Mark Hamill. The investigation leads Batman and Bullock to Arkham Asylum, where they encounter a fully masked Joker, only to realize it’s a decoy.

We delve into Joker’s past, where he was once a struggling comedian supporting his pregnant wife, Jeannie, voiced by Anna Vocino, while battling financial hardships. As the plot unfolds, the Joker’s corruption spirals from personal losses and tragedies that unfold in flashbacks, revealing the depths of his madness.

In a shocking twist, the Joker confronts Barbara in her home, inflicting a devastating injury that forever alters her life trajectory. As chaos reigns during Gordon’s abduction, Barbara defies her fate, grappling with her trauma while embroiled in the Joker’s twisted games.

The Joker, refusing to release his grasp on Gordon’s sanity, conducts a gruesome torture routine, using visceral imagery to torment him. Meanwhile, Batman races against time to save Gordon from the Joker’s horrific amusement park, reliving his own origins intertwined with Joker’s chaos.

Their confrontation escalates into a chaotic struggle amidst the Joker’s twisted narrative, which culminates in Batman flinging both himself and the Joker out of a window in a moment of mutual realization. As they share laughter amidst chaos, Batman sees the chaos of their existence reflected back at him.

The story closes with Barbara adjusting to her new reality in a wheelchair. She enters her room to her computer, with the Oracle logo marking the beginning of her new journey, setting the stage for her to embrace a different kind of heroism.