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.
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. Batman- The Killing Joke
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. Inside the plant, the heist goes wrong
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." When he pulls off the mask, he looks
Through it all, Gordon remains defiant. Covered in sweat, blood, and filth, he keeps repeating a single phrase: "I want him brought in by the book." He refuses to break. He refuses to become the Joker. Intercut with this horror is a flashback—the Joker’s "possible" origin. Moore is careful to frame it as unreliable: "Something like that... happened to me, you know? I'm not sure. I... I remember it differently. But... it's not bad." We see a failed comedian, desperate to support his pregnant wife, Jeannie. He agrees to guide two criminals through a chemical plant as "Red Hood" to score a big payday. On the night of the heist, police tell him his wife has died in a household accident. Grief-stricken, he tries to back out, but the criminals force him to proceed.
The Joker argues yes. Gordon argues no. Batman stands in between, holding a flashlight, unsure if he’s guiding the way or just illuminating the abyss. In the end, the joke is on the reader. We came for a superhero story, but we left with a meditation on the fragility of the human mind. We laughed at the punchline, but the laughter echoes in an empty, rain-slicked alley.
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.