Short answer: Arthur Fleck murders talk-show host Murray Franklin live on television, sparking riots across Gotham. A clown-masked crowd pulls Arthur from a police car and hails him as a symbol, and the film ends with Arthur back in Arkham State Hospital, laughing at a joke he refuses to share. How much of that final stretch is real is deliberately left open. Full spoilers follow.
The road to the ending
Arthur is a struggling party clown and would-be comedian whose care support is cut off and whose medication runs out. Fired after taking a gun into a children’s hospital, he is attacked on a subway train and shoots three Wayne Enterprises employees, becoming, anonymously, a folk hero to Gotham’s angry poor, many of whom adopt clown masks.
Two discoveries push him over the edge. His mother Penny’s records suggest Arthur was adopted and abused as a child, undercutting her claim that Thomas Wayne is his father. And his relationship with neighbour Sophie was never real: to her, he was the strange man down the hall. He suffocates his mother and kills Randall, the colleague who gave him the gun. Invited onto The Murray Franklin Show after footage of his disastrous stand-up set becomes a hit, he has decided the appearance will be his final act.
The Murray Franklin Show
Arthur arrives in full Joker make-up and a rust-red suit, dancing down a flight of steps. Murray, who once mocked Arthur’s comedy on air, tries to keep things light. Arthur instead delivers a furious speech about a society that laughs at people like him and then abandons them, says he killed the three men on the subway because they were awful, and shoots Murray in the head on live television. The broadcast cuts out, and Arthur is arrested.
The riots and the car bonnet
The murder is the spark Gotham was waiting for. Clown-masked protesters flood the streets while Arthur is driven away in a police car. A hijacked ambulance, driven by protesters, smashes into the car, and the crowd drags an unconscious Arthur from the wreckage. When he comes round, he climbs onto the bonnet and smears his own blood into a wide red grin as the crowd cheers him like a leader.
The Waynes in the alley
Intercut with the riot, Thomas, Martha and young Bruce Wayne leave a theatre and slip into an alley. A clown-masked gunman, angered by Thomas Wayne’s dismissive remarks about Gotham’s poor, shoots Thomas and Martha, and Bruce is left standing over his parents’ bodies. It is the classic Batman origin, retold with a twist: Arthur’s chaos claims the Waynes — in a dark sense, the Joker creates Batman.
The final Arkham scene
The film cuts, without explanation, to Arthur in a white room at Arkham, sitting across from a social worker. He begins to laugh. Asked what is funny, he says he was thinking of a joke, then stops himself: she “wouldn’t get it.” As he laughs, the film flashes to young Bruce over his dead parents. Arthur then walks down a corridor, leaving bloody footprints — strongly implying he has attacked the worker — before an orderly gives chase and he runs, laughing, out of frame.
What the ending means: three competing readings
1. It all happened. On the literal reading, Arthur really killed Murray, really was raised up by the crowd, and really was recaptured and committed to Arkham. The bloody footprints are the grim punchline.
2. It was all in Arthur’s head. Arthur is unreliable throughout: he imagines himself as a celebrated guest on Murray’s show long before any real invitation, and his relationship with Sophie turns out to be fantasy. Some viewers therefore read the whole story — or at least its triumphant final act — as a delusion dreamed up by a man already locked inside Arkham. Director Todd Phillips has refused to settle the question, saying audiences are presented with possibilities rather than facts.
3. A mix of real and imagined. The middle reading is that some events are real and others embellished by Arthur’s mind. The film confirms the Sophie fantasy explicitly, but never confirms the Murray murder or the riot were imagined. On this reading, the Arkham scene is real — Arthur ends up captured whatever else happened — while the scale of his adoration may be partly his own retelling. A further wrinkle: because Bruce is still a child and Arthur is in his thirties, some argue Arthur may inspire the “real” Joker rather than being that Joker himself.
Frequently asked questions
Did Arthur kill Sophie? The film never shows it. After the fantasy collapses, the scene ends without revealing what happens next.
Is Arthur really Thomas Wayne’s son? The evidence points the other way: Thomas denies it, and Penny’s records describe Arthur as adopted. The film treats the son theory as one of Penny’s delusions.
What is the joke in the final scene? The film never tells us. The cut to young Bruce over his parents’ bodies suggests Arthur finds something darkly funny in the idea that his chaos created the boy who will become Batman — but he refuses to explain it.
Does the ending set up a sequel? The follow-up, Joker: Folie à Deux (2024), picks up Arthur’s story inside Arkham.