Phoenix goes Gaga in first Joker: Folie A Deux trailer

They say that love conquers all, but does that include madness? That question looks to be a central theme of Joker: Folie A Deux, the sequel to the 2019 Joker which features the return of Joaquin Phoenix alongside co-writer and director Todd Philips. The pair also welcome newcomer Lady Gaga as Harley Quinn.

The original film proved controversial, but also wildly successful as it earned over a billion dollars worldwide, making it the highest earning R-rated film of all time. A Batman-less origin story for the Dark Knight's arch enemy, Joker showed how clown Arthur Fleck went from a delusional wannabee comedian to the face of a social movement he never intended. Along the way, he developed an aptitude for murder as well as the iconic purple suit and grease paint that have been thrilling comic readers since the character debuted way back in 1940.

The sequel, which looks to incorporate classic musical visual elements into the gritty 1970s style implemented in the first, appears to open with Fleck in Arkham Asylum where he meets and falls for Lady Gaga's Harley Quinn. The pair of star-crossed maniacs dance their way through the trailer and Gotham on what will surely prove to be another murderous outing. However, as viewers who watched the initial film will remember, Fleck's not exactly securely tethered to reality, so maybe some of this takes place in his head.

Philips has already shown an interest in building new versions of these famous characters, using elements from the comics. In the source material as well as Batman: The Animated Series -- where Harley actually debuted -- Quinn started out as Dr. Harleen Quinzel, a psychologist at Arkham. While attempting to care for the Clown Prince of Crime, she fell in love with him, helped break him out and they started a whirlwind on-again, off-again relationship.

Harley was a big hit with audiences and has become one of the biggest players in the Batman Universe. She's lead a number of comic book series', appeared in just about every subsequent cartoon and even headlines her own with Big Bang Theory star Kaley Cuoco voicing the character. Most prominently, Harley Quinn was played by Margot Robbie in Suicide Squad, Birds Of Prey and The Suicide Squad, but that cinematic universe has been shuttered.

Singer-turned-actress Gaga will be the latest performer to bring Harley Quinn to life. As a performer, her style often dipped into darker arenas, but she went fully into scaresville by appearing in the fifth season of American Horror Story, a performance which earned her a Best Actress Mini-Series or TV Film Golden Globe. She returned for the following season as well.

Gaga and Phoenix will be joined by Zazie Beetz, who played Sophie Dumond in the first film, as well as Katherine Keener (Get Out, The 40-Year-Old Virgin), Brendan Gleeson (Mr. Mercedes, The Village), Ken Leung (Lost, Avatar: The Last Airbender) and Steve Coogan (Alan Partridge, Night At The Museum), an interesting mix of very funny actors and dramatic experts.

Joker: Folie A Deux is scheduled for an October 4, 2024 release.