The film “Joker,” starring Joaquin Phoenix, portrays how access to treatment is directly correlated to income.

“Joker” is a deeply disturbing, wholly unsettling profile of villainy masked as popcorn entertainment. Director Todd Phillips Trojan Horses a story about a mentally unstable loner gone mad in a cruel, unforgiving world into a blockbuster origin story about everyone’s favorite Batman villain.

It’s bold, it’s daring, it’s subversive and it’s thrilling. But it ain’t no comic book movie.

Joaquin Phoenix gives the year’s most haunting performance as Arthur Fleck, the rent-a-clown who inspires a people’s uprising. Or maybe he doesn’t. “Joker” holds some cards close to its chest, and there are questions about what unfolds in reality and what transpires inside Fleck’s mind.

But Phoenix is so unforgettable as Fleck that he makes previous iterations of this character — including Heath Ledger’s Oscar-winning turn in “The Dark Knight” — look like the actors playing him were just clowning around.

As Arthur, Phoenix moves like Jagger, twisting and turning his body like his bones are made of elastic. In silhouette, he looks like a contortionist who can bend into any shape he pleases. But Phoenix’s greatest asset is his face, hollowed out and gaunt, his eyes sunken in and empty. Arthur’s laugh — involuntary and oftentimes inappropriate — is part of a medical condition for which he apologizes by handing strangers a typed explanation. It’s more a cry than it is a chuckle.

It’s 1981 and things are ugly in Gotham City. Super rats are taking over the streets, savage thugs will mug a stranger for loose change, and the rich are getting richer off the backs of the poor. The parallels to today are not coincidental, they’re the whole point.

Phillips frames his Gotham City as a grungy, skeezy homage to Scorsese’s New York of “Taxi Driver” and “The King of Comedy” so blatantly that he has to cast Robert De Niro as Murray Franklin, Gotham’s top talk-show host. Arthur watches Franklin with his mother Penny (Frances Conroy) and dreams of one day sitting on his couch as a guest once his comedy career takes off.

Arthur’s notebooks of joke material read more like the deranged scribbles of a psychopath. On stage at an open mic night, he makes even an empty room squirm with discomfort. He’s alone in his world, his alienation his closet friend. When he comes across a couple of Wall Street-frat boy types and kills them following an altercation gone sideways, he begins, for the first time, to walk with purpose.

Since this is “Joker,” after all, Phillips and co-writer Scott Silver do need to find a way to weave Batman into their script, but don’t expect Arthur to take a swan dive into a big vat of acid.

Phillips is far more interested in Arthur’s mind, and the radicalization of a fringe personality. How and why does one become an agent of evil? In “Joker,” everyone’s to blame, and Phillips sees a society tearing itself apart as the canvas on which the Joker is painted.

The rich are corrupt, the system is rigged, burn it all down. And Joker is the match.