Summary
Arthur returns home and has a vision of Sophie pantomiming shooting herself in the head on the elevator. He lets himself into Sophie's apartment, and when she finds him on her couch, she is startled that he is there. "Your name's Arthur, right? You live down the hall," she says, and we suddenly realize that their entire relationship has all been in Arthur's head. She begs him to leave and he tells her he had a bad day, before holding his hand up to his head, miming shooting himself.
He leaves abruptly and goes to his mother's apartment, where he laughs maniacally while sitting on the couch. The next day he visits his mother at the hospital. She is barely conscious, but she calls his name, "Happy." He replies, "I haven't been happy one minute of my entire fucking life." He stands and tells Penny that his life is not a tragedy, but a comedy, as he smothers her to death with her pillow.
Arthur goes home and watches old footage of the Murray Franklin Show. He practices what he will do on the talk show, and imagines himself telling a joke and then pulling out a gun to shoot himself on television. In his imagination, he hears the audience laughing and cheering when he kills himself.
As "That's Life" by Frank Sinatra plays, we see Arthur dying his hair green and dancing in his bathroom. He paints his face white, even his tongue, then looks at a photograph of his mother, crinkling it up in his hand. Suddenly, his doorbell rings, and he puts a pair of scissors in his back pocket to answer it. It's Randall and Gary, his former coworkers. They offer their condolences about his mother, but Randall soon begins talking about the fact that the detectives have been coming to his apartment. When Arthur realizes that Randall has only come to find a way to cover for himself in the subway murders, he stabs Randall brutally in the face. Gary begs Arthur to let him go, and Arthur agrees, but Gary cannot unlock the door himself. Before he lets Gary go, Arthur thanks him for being kind to him, kissing his forehead.
Arthur goes outside in full clown makeup and a suit. He dances wildly down the staircase outside his apartment building. The two detectives spot him and yell to him that they want to talk. He runs away from them, frightened, getting hit by a cab in the midst of the chase. He manages to stand and keep running, fleeing onto a subway that is filled with other people—protestors, all dressed as clowns.
The detectives chase Arthur through the train, and Arthur steals one of the clown protestor's masks, creating a physical fight. One of the detectives accidentally shoots one of the clown protestors, and the clown protestors pull the cops out of the train car, beating them up. Arthur sneaks away, completely unnoticed by the cops walking past him.
Arthur goes to The Murray Franklin Show and waits in his dressing room, where he meets Murray himself. "What's with the face? Are you part of the protest?" Murray asks, and Arthur begins to cry, telling his television idol that he doesn't believe in "any of that." Before Murray goes, Arthur asks him to introduce him as "Joker," when he brings him on, a reference to the fact that Murray called him "Joker" on the show when he first talked about him.
Analysis
Arthur's life keeps getting worse when he lets himself into Sophie's apartment and the viewer realizes that they were never in a relationship at all—it was all in Arthur's head. Sophie is shocked to see him and acts as though she barely knows him, which tips us off to the fact that Arthur's relationship with her has been a complete delusion, a figment of his imagination. It is a terrifying and disorienting reversal, as we realize just how implausible their relationship was to begin with. Suddenly, Arthur turns into his delusional mother, Penny, imagining a relationship where there never was one.
As soon as Arthur becomes like Penny, he wants desperately to extinguish her. In a particularly disturbing and terrifying scene, he visits his mother at the hospital and smothers her with her pillow, just after delivering one of the most haunting lines of the film: "I used to think my life was a tragedy, but now I know that it's a fucking comedy." It is this moment of matricide that the viewer sees Arthur fully become the horrifying villain that he has been threatening to become throughout the film. No longer focusing on the systems that have kept him and his mother down and have prevented them from finding adequate care, he externalizes his despair and takes it out on his mother, a victim of mental illness herself.
One of the confusing and haunting elements of the film is the fact that Arthur's descent into complete psychopathy coincides with a boost in confidence and a renewed sense of self. Immediately after killing his mother and imagining killing himself on television, we see Arthur dancing around his apartment and putting on his Joker makeup as though it is warpaint. This is the most joyous and confident we have seen Arthur in the whole film, even if it is a demented and offbeat joy. Phillips presents Joker's evil as a state of becoming and blossoming into a sense of self, a claiming of his power, however dark and twisted that power may be.
This descent into madness is accompanied by a full costume change and musical number. After brutally killing his old coworker Randall, Arthur dons a burgundy suit, full clown makeup and green hair, and dances down a staircase in a larger-than-life style. It is a startling image of a man who has been pushed into madness and embraced it, who is finally feeling pleasure, but only through a perverse connection to violence and chaos. This transformation feels not unlike the transformation of Travis Bickle in Martin Scorsese's Taxi Driver, when he goes from ordinary (if marginal) citizen to ruthless killer.
The other irony of Arthur's descent into madness is the fact that it is connected to a broader political movement in the city, which he unintentionally began. When he flees the two detectives onto the subway car, nearly everyone else on the car is dressed as a clown, as it has become the uniform of resistance in Gotham. While Arthur's political acts of vigilantism are more inadvertent and chaotic than the organized movement he has stoked, he is supported by this general resistance to authority, and it is what allows him to continue doing harm without consequence. Part of what allows him to thrive as an agent of chaos is the fact that Arthur has tapped into a collective desire for chaos and revolution against the unjust political system of Gotham.
