The Joker’s goal is not to kill Gordon. It’s to break him. He takes Gordon to the "Joker’s Funhouse"—a nightmarish, grotesque carnival—and subjects him to a relentless parade of psychological torture. He shows Gordon the photographs of Barbara. He forces him to walk a tightrope over a pool of alligators. He straps him to a chair and forces him to look at distorted, funhouse-mirror versions of his own trauma.
Inside the plant, the heist goes wrong. Batman appears. The terrified Red Hood jumps into a vat of chemical waste to escape, only to be flushed out into a drainage basin. When he pulls off the mask, he looks into a mirror—and sees the Joker for the first time: bleached-white skin, ruby-red lips, green hair. His "one bad day" has physically and mentally unmade him.
Immediately after, the Joker escapes (or is he released? The story is ambiguous). He purchases a decrepit amusement park, then executes his most personal attack yet. He arrives at Commissioner Gordon’s home, shoots Barbara Gordon (Batgirl) through the spine, shattering her vertebrae and leaving her paralyzed. He then strips her, takes photographs of her wounded, naked body, and kidnaps Commissioner Gordon. Batman- The Killing Joke
Moore was approached to write a Joker story. Initially reluctant, he was intrigued by the idea of giving the Joker a definitive origin—something that had only been hinted at in past comics (most notably in 1951’s "The Man Behind the Red Hood!" by Bill Finger and Lew Sayre Schwartz). Moore’s concept was bleakly simple: to explore the thesis that anyone, even the most upright citizen, is just "one bad day" away from complete insanity.
The Joker pauses. For a moment, he seems almost defeated. Then, he tells a final joke: "See, there were these two guys in a lunatic asylum... and one night, one night they decide they don't like living in an asylum any more. They decide they're going to escape! So, like, they get up onto the roof, and there, just across this narrow gap, they see the rooftops of the town... stretching away in the moonlight... stretching away to freedom. Now, the first guy, he jumps right across with no problem. But his friend, his friend didn't dare make the leap. Y'see... he was afraid of falling. So the first guy gets an idea. He says, 'Hey! I have my flashlight with me! I'll shine it across the gap between the buildings. You can walk along the beam and join me!' B-but the second guy just shakes his head. He suh-says... he says, 'Wh-what do you think I am? Crazy? You'd turn it off when I was half-way across!'" Batman laughs. It’s a genuine, surprised laugh. The Joker laughs too. Their laughter echoes in the rain. As the sound fades, the panels zoom out, and the last image is of Batman’s hands reaching for the Joker’s throat—but are they wrestling? Are they embracing? The final page shows the police lights reflecting in a puddle, and the laughter stops. The Joker’s goal is not to kill Gordon
Batman confronts the Joker. Their final exchange is not a fight but a philosophical debate. Batman says, "Maybe it's just you. Maybe you're the one who couldn't cope with a bad day." He offers again to rehabilitate the Joker, to end their cycle of violence.
Alan Moore himself has expressed regret over the violence done to Barbara, calling it "shallow" and "clumsy" in retrospect. "I made it too cruel," he said in a later interview. "I wouldn't write it that way now." He shows Gordon the photographs of Barbara
In the pantheon of graphic novels, few works have burrowed under the skin of popular culture quite like Batman: The Killing Joke . Published in 1988, written by Alan Moore, illustrated by Brian Bolland, and colored by John Higgins, this 48-page one-shot was intended to be a definitive origin story for the Joker. Instead, it became a controversial masterpiece—a grim, psychological horror story that permanently altered the relationship between Batman and his greatest foe. It gave us iconic lines ("All it takes is one bad day to reduce the sanest man alive to lunacy"), horrifying images (the crippling of Barbara Gordon), and an ending that has been debated for three decades.
The tragedy is that we don’t know if this is true. The Joker himself admits he prefers his origin to be "multiple choice." This ambiguity is key. The Joker isn't a tragic figure because of what happened to him; he's terrifying because he chose to become a monster in response to his pain. He argues that everyone would make the same choice. He uses his origin as a weapon to prove that order is a lie. Batman, having tracked the Joker to the funhouse, fights his way through carnival-themed death traps. He finally finds Gordon, strapped to a twisted version of a carousel horse. Gordon, eyes hollow but spirit unbroken, gives Batman the order: "Bring him in by the book." He refuses to let Batman kill the Joker, proving that the Joker’s experiment has failed.