Opening Image
Arthur (Joaquin Phoenix) cracks up in front of his social worker at the Dept. of Health. His medical condition is apparent; he’s looking for help: “I just don’t want to feel so bad anymore.”

Catalyst
Arthur holds an ‘Everything Must Go’ sign on the street in a clown outfit. A group of guys runs off with his sign—the current source of his livelihood. When Arthur desperately chases them to get his sign back, they break the sign on his head and give him a beating. It’s the beginning of the end for Arthur. This violent unkindness launches an avalanche that will increasingly threaten Everything—his sign, his job, his pride, his sanity. His call to action is to do something about it.

This Catalyst moment has a one-two punch. It will be complete when Randall offers him a gun for his protection—the thing that will eventually propel him from the edge of Act I into Act II.

Set-up
Joker has a beautifully expressive, methodical set-up. In scene after scene, we not only get to know Arthur, his colleagues, his mother (Frances Conroy), and the environment and society he lives in, but also feel his growing sense of loss and desperation. His neurological condition is expressed in a heartbreaking ‘Save the Cat’ moment on a bus, as he tries to make a child laugh but gets scolded.

The piles of garbage on the streets are physical and metaphorical manifestations of the level of poverty, neglect, intolerance and violence in Gotham. People are angry and on edge.

We’re also introduced to Arthur’s fantasy world, his escape from all of this. He longs to be acknowledged by his idol, TV show host Murray Franklin (Robert De Niro). He wants to hear that he’s special, that it’s okay that he lives with his mother because he takes good care of her like a responsible son. He wants his purpose and desire in life to be recognized: to bring laughter and joy to people. He wants a father who accepts him; that father figure is Murray in his fantasy. Becoming a successful stand-up and dating his neighbor Sophie (Zazie Beetz) are also parts of this fantasy world, in which he’s understood, respected and loved.

Theme Stated
As a result of losing his sign, Arthur gets a warning at work. But even more strangely, his beating inspires his colleague Randall (Glenn Fleshler) to conspire against him. Knowing Arthur is not supposed to carry a gun Randall gives him one, acting like he’s doing Arthur a favor. The gist of Randall’s advice to Arthur is ‘if you show empathy and tolerate people’s wrong-doings, they’ll take everything from you.’ For the rest of the story Arthur tries to figure out if this is true: Should he succumb to what’s going on around him even though it hurts, or should he take matters into his own hands and fight back?

Debate
Arthur’s first debate question is: is he going to be pushed to his limits enough to use the gun Randall gave him? Is he going to blow over? Second, can he become who he wants to become? Is he a comedian? In a Taxi Driver-esque moment he gets a feel for his gun, pointing it at things. But he fires it by mistake as if the gun is more powerful than he. As he battles with his depression, we see he’s on the verge of suicide, bringing into light a third and bigger debate: should he kill himself?

Then he finds out about Randall’s betrayal: Randall gave him the gun specifically to get him fired. Arthur loses his job, possibly the only thing that tethers him to reality and sanity. And this final push tips him over into:

Break into Two
Arthur gets provoked on the subway. After clinging to his usual avoid-and-retreat tactics as long as he could, he ends up killing the three Wall Street guys who mess with him. His reaction surprises even Arthur at first, but by the third guy he’s intoxicated by his newfound power.

Fun & Games
The first sign of ‘fun’ in Arthur’s life comes immediately following the First Act Break—his first set of murders and taste for his alter-ego Joker. In a public bathroom he’s elated, finally alive. The first seed of violence has been planted; the change has begun. From here on out, he grows more confident, powerful, cocky. Even society is suddenly noticing him, applauding him. His fantasy world begins to intersect his reality when people glorify Joker and what he stands for.

Meanwhile, Gotham continues to deal Arthur blow after blow: his social worker abandons him because of budget cuts; his treatment and medications are cut off. His comedy act isn’t great either, but at least Sophie thinks “the guy who killed the Wall Street Three is a hero.” Arthur continues to be ignored and ridiculed by society, whereas Joker is bathed in fame and glory.

The gap between his Arthur-self and Joker-self widens.

B Story
B Story is generally known to be the love story, and in Joker there is one: Arthur’s fledgling relationship with Sophie. But B Story is also the story beat where the theme of the story is discussed and explored. Considering that Arthur’s relationship with Sophie is revealed to be another figment of his imagination, and because it doesn’t carry the weight of the themes of injustice and revenge, I will propose that the B Story of the film is Arthur’s relationship with his alter-ego, Joker.

It indeed resembles a romantic relationship, where he’s lured by Joker’s power and confidence, indifference and violence, all the qualities that will allow him to not only survive Gotham but also excel in it by receiving attention, recognition, respect and love. Arthur’s only chance of being complete and happy might be through achieving union with Joker.

Arthur’s relationship with Joker is where the theme of the story is tested: Show empathy and swallow injustice or fight back with anger and revenge. Slowly but surely Arthur’s delicate spirit which has no place in a society like Gotham gives way to Joker’s violent spirit spreading like wildfire all over the city. It’s almost as if the film’s theory is ‘evil attracts evil’; as long as the environment is corrupt and violent it will be fueled by things of the same nature and spit out foreign elements like Arthur. Arthur needs to be discarded because he doesn’t fit in Gotham, and Joker is what Gotham craves for and ultimately deserves.

Midpoint
Arthur finds out that Thomas Wayne—the future mayor—is his father (Brett Cullen). He takes this as shocking news as he thought of his mother’s obsession with Wayne as hopeful at best. But now he suddenly has a sense of belonging, a chance at being somebody. His Arthur-self is back in action when he senses a possibility for being a normal person with a father and a future. His new goal is to connect with his father and be acknowledged as a son. This is his only chance at turning his back on his budding Joker-self.

Bad Guys Close in
From Midpoint on there’s an avalanche of disappointments in Arthur’s life, pushing him closer and closer to his inevitable fate. He confronts his mother; she says, if people knew he was Wayne’s son, they would think he’s an ‘unwanted bastard’. He then confronts Wayne’s angelic, well-looked after son—the son that he could have been. He gets laughed at for even thinking Wayne could be his father.

On the other hand, the detectives are onto him asking questions. Hearing what Arthur might have done, his mother has a stroke. Murray, his idealized father figure, plays a recording of his stand-up and makes fun of him on TV. Gotham City is getting crazier; the violence and hatred on the streets are sky-high.

Despite everything, Arthur reaches out to his father. Predictably, Wayne does not embrace him as a son. Instead, he tells him he was adopted, that his mother is an institutionalized mental health patient.

From hospital records Arthur gleans further information about his past. He finds out his mother was accused of endangering the welfare of a child, that her neglect is what made him sick. It’s also revealed here that his romance with Sophie was imagined, echoing his mother’s alleged delusions about Wayne.

All this is too much for Arthur; he must do something, regain his balance somehow…

All is Lost
Arthur’s identity crisis is at its peak. He confronts his mother about who he is, and then kills her in her hospital bed. The only person who truly loved him is gone.

Dark Night of the Soul
Arthur practices his new identity as Joker—his transformation is well underway. He plans his appearance on Murray’s TV show, what he will say, how he will present himself, how his dream will finally come true, how he will kill himself…

Break into Three
Arthur puts on his Joker make-up; he dyes his hair green and his face white, plants a menacing smile on his face. This time he will not drift into Joker; his transformation will not be accidental. He will now wear Joker’s mask with intention; he will willingly embody him.

As he’s busy with his transformation, an opportunity arrives at his door: Randall pays him a visit and Joker kills him. There is poetic justice in his first kill as a truly-transformed-Joker, because Randall was the man who betrayed and pushed him into the abyss of evil in the first place, and now his 1st act self (Arthur) and 2nd act-emerging-self (Joker) merge with the death of the person who catalyzed his transformation.

Finale
Joker on the Murray show. There is no sign of Arthur in this new persona. He’s confident, cunning, disturbing, a full-on psychopath. The people of Gotham are aligned with Joker; Gotham found a home in him and finally he is at home in Gotham. As Joker openly criticizes the society, the system in Gotham, we believe it too: violence works, evil is king in this place.

The fully transformed Joker doesn’t kill himself like a tragic character; he kills Murray instead, his lifelong father figure and idol.

Joker later comments for the newspapers that his killing of Murray was a punchline to a joke, indicating he has no empathy left and cementing his life as a comedy. The thematic question of the film is now resolved: Arthur chose Joker.

Final Image
Joker is institutionalized. Mirroring the Opening Image of the film where he sat across from a social worker, he now sits in front of a psychiatrist at a hospital. But this time he has no words in his journal; he does not want to feel understood; he has no use for empathy.

Gotham has devoured Arthur; Joker is all that remains. In Joker’s words: “Isn’t it beautiful.”