Batman: Mask of the Phantasm

Andrea left Gotham with her father Carl because Carl had gotten involved in dangerous financial dealings with Gotham's criminal underworld, including Salvatore Valestra, Chuckie Sol, and Buzz Bronski. When Valestra demanded "payment in blood" from those who crossed him, Carl and Andrea were forced to flee to Europe to escape the consequences of his debts.

Earlier, Bruce finds a photo of Carl with the three criminals, revealing the shady deals that forced their departure.

The Phantasm is Andrea Beaumont. She returned to Gotham after her father's death to systematically eliminate the criminals responsible for his demise - Chuckie Sol, Buzz Bronski, and Salvatore Valestra - all of whom were part of the criminal alliance that betrayed her father.

The Phantasm strikes at a cemetery where Andrea and Bruce previously visited their family graves, hinting at her connection to that location.

The Phantasm is seeking revenge for her father's murder. Carl Beaumont was killed by the Joker after being betrayed by his criminal associates (Sol, Bronski, and Valestra). Andrea discovered that these men had orchestrated her father's death and returned as the Phantasm to kill them one by one.

The Phantasm's victims - Sol, Bronski, and Valestra - are all connected to Carl through the photo Bruce finds in Valestra's hideout.

The Joker killed Salvatore Valestra with Joker venom. Valestra, frightened after learning Bruce Wayne was investigating the criminal conspiracy, sought help from the Joker. Instead of protecting him, the Joker poisoned Valestra with his signature venom, killing him before the Phantasm could reach him.

When the Phantasm infiltrates Valestra's penthouse, she finds him already dead with green venom on his face.

The police believe Batman is the Phantasm because witnesses at Chuckie Sol's crash scene mistakenly identified Batman as the masked figure who caused the deadly accident. City councilman Arthur Reeves, who had his own reasons to want Batman discredited, actively pushes for Batman's arrest, leading the GCPD to target the Dark Knight.

The mistaken identity at Sol's crash sets the narrative in motion for Batman's wrongful pursuit.

Carl Beaumont had partnered with three of Gotham's most dangerous criminals - Chuckie Sol, Buzz Bronski, and Salvatore Valestra - in some kind of financial scheme. When their operations collapsed or when Valestra demanded payment, Carl fled Gotham with Andrea. Years later, the Joker killed Carl, and the surviving criminals were eliminated by Andrea as the Phantasm.

Bruce discovers a damning photo of the four men together in Valestra's hideout, confirming their connection.

Arthur Reeves, a city councilman, had been bribed by the criminals, particularly Carl Beaumont, to protect their operations. When Reeves feared his involvement would be exposed, he betrayed Carl by alerting the criminals to his location, indirectly leading to Carl's murder at the Joker's hands. Reeves later tries to cover his tracks by supporting the anti-Batman crusade.

Reeves conveniently pushes for Batman's arrest while secretly knowing the truth about the Phantasm.

After faking her and her father's departure from Gotham, Andrea later returned alone, presumably after her father was killed. She created the Phantasm identity and armor, using her knowledge of the criminal underworld to track down and eliminate the men responsible for her father's death. She operated in secret, even keeping her identity hidden from Bruce until the climax.

The Phantasm's combat skills and knowledge of criminal hideouts suggest prior preparation and investigation.

Andrea dies in the explosion at the Joker's abandoned World's Fair lair. When Batman arrives to stop the Joker's plan, Andrea attempts to kill the Joker but is caught in the explosion when the Joker's own device detonates. Bruce escapes, but Andrea's fate is left tragic and unresolved - Alfred tells Bruce that Andrea's destiny was sealed long before, beyond anyone's control.

Batman pleads with Andrea to abandon her vendetta, but she refuses, setting up her tragic fate.

The Joker targets Batman as part of a broader scheme to eliminate everyone connected to his past. Salvatore Valestra hired the Joker to kill both Batman and the Phantasm. The Joker sees both vigilantes as threats and sets traps at Valestra's penthouse and his lair to destroy them, though his plans consistently backfire.

The Joker's involvement was requested by Valestra when he felt threatened by Bruce's investigation.

Bruce trusts Andrea completely and wants to be honest with her given their rekindled relationship. When Andrea returns to Gotham and Bruce meets her again as Batman, he chooses to reveal his identity rather than continue the deception, believing their connection warrants full transparency.

Their earlier bond at the family graves established deep trust between them.

Bruce cannot save Andrea because her desire for vengeance is too deeply rooted in her grief and anger over her father's murder. Despite Batman's pleas at the Joker's lair to abandon her vendetta, Andrea remains steadfast in her quest for revenge. Alfred later explains that Andrea's fate was sealed long ago - her path was set when her father was killed, and nothing Bruce could say could change that trajectory.

Andrea's repeated refusal to stop, even when confronted directly by Batman, shows her commitment to revenge over everything else.