Joker 2: What Does Folie à Deux Mean & Why Is It Important?

It's already been several years since Joaquin Phoenix first transformed into the Joker, an arduous endeavor that earned him an Academy Award. The veteran actor's lauded performance in 2019's "Joker" helped propel the film to critical acclaim and box-office glory, as it became one of the few DC films to earn over $1 billion. Now, Phoenix is gearing up to don that iconic crimson grin once more, except this time, he's joined by fellow Oscar winner Lady Gaga, who's stepping up as the one and only Harley Quinn.

Gotham's most notorious criminal duo takes center stage in the sequel "Joker: Folie à Deux," which premieres on October 4, 2024. The title takes the French phrase "madness of two" — or "folly of two," a term commonly used to describe a psychological disorder in which two individuals with strong ties (married couple, siblings, best friends, etc.) share in a similar delusion. Now, it doesn't take a comic book scholar to immediately recognize that this is a perfectly apt summarization of Joker and Harley's relationship.

How will Joker and Harley's relationship be portrayed in Folie à Deux?

In comic books, animated shows, video games, and live-action films, the relationship between Joker and Harley Quinn has often been one of abuse and neglect, with the Clown Prince of Crime being, quite literally, the world's most toxic partner. In recent years, projects like Max's "Harley Quinn" animated series and 2020's critically-praised "Birds of Prey" have put the spotlight on the latter's rise as a standalone antihero free from Joker's sadistic clutches.

"Joker: Folie à Deux" has an opportunity to do something different. In most "Batman" stories, Joker is often seen as the corruptive force that seduces the good doctor Harleen Quinzel into a life of crime. In "Folie à Deux," things do not have to be so straightforward. Given the events of the first film, what if Arthur Fleck has more or less become indifferent toward his past criminal actions, only for a new gaga (sorry) of an inmate urging him to embrace his chaotic persona once more? Or, following its uber-appropriate title, "Folie à Deux" could portray two delusional souls feeding into each other's respective delusions.

No matter which route "Joker: Folie à Deux" goes with Joker and Harley Quinn's relationship, there's a strong chance it won't be like anything fans have seen before.