Joker: Folie à Deux trailer breakdown – is it a musical, who is Lady Gaga playing and your biggest questions answered

Arthur Fleck smiles with his clown makeup on as he wears a white suit in Joker: Folie a Deux
Joker: Folie à Deux's first trailer has been watched by millions of people since its release. (Image credit: Warner Bros. Pictures)

Possible spoilers follow for Joker: Folie à Deux.

The first trailer for Joker: Folie à Deux, one of 2024's most anticipated new movies, has finally been unleashed on the world, and it's as beautifully unsettling as we'd expected it to be.

Released online after its worldwide debut at Warner Bros. Pictures' 2024 CinemaCon presentation, the teaser gives us our first official look at the sequel to 2019's billion-dollar making Joker. And, while the DC Elseworlds movie's first trailer doesn't give too much away about its plot – it's only a teaser, after all – there's enough we can glean from its footage to answer the most pressing questions you have about the follow-up to one of the best superhero movies (that's subjective, mind you) ever made.

Before we provide answers to your queries, take a look at the Todd Phillips-directed film, which stars Lady Gaga alongside the returning Joaquin Phoenix, below:

Is Joker 2 going to be a musical?

Harley Quinn and Arthur Fleck dance on a rooftop in Joker: Folie a Deux

Joker 2 won't be a full-blown musical. (Image credit: Warner Bros. Pictures)

That's the biggest question on everyone's lips after the release of Folie à Deux's first teaser. In recent months, fans have speculated that Joker 2 would be a musical, owing to the fact that Lady Gaga (more on her later) would co-star in it and that a recent Variety article suggested its soundtrack would "reinterpret" 15 classic songs, including That's Entertainment from the 1953 musical The Band Wagon.

So, is Joker: Folie à Deux a full-blown musical? In short, no. Speaking during Warner Bros' CinemaCon panel, director Todd Phillips said (per Entertainment Weekly): "We never really talked about it like that [being a musical], but I like to say it's a film where music is an essential element". If you were expecting an unhinged version of La La Land, then, you might want to rein in your expectations.

Who is Lady Gaga playing in Joker: Folie à Deux?

Harley Quinn passes a baying mob as she walks up some steps in Joker: Folie a Deux

Harley Quinn's origins story has been changed for Joker 2. (Image credit: Warner Bros. Pictures)

She's playing someone that fans – comic book aficionados and otherwise – know very well: Harleen Quinzel, aka Harley Quinn. 

However, the infamous Clown Princess of Crime's origin story has been altered for this film. Indeed, Lady Gaga's Quinzel won't start out as a psychiatrist who becomes infatuated with Phoenix's Arthur Fleck/Joker and eventually joins his cause to bring chaos to Gotham City. Instead, Quinzel will be one of Fleck's fellow inmates at Arkahm Asylum.

The trailer suggests that the pair will fall in love and get embroiled in all kinds of shenanigans in Folie à Deux, but is it all a ruse? We know Fleck is an unreliable narrator/untrustworthy protagonist who lives a life of illusion – he proved as much in 2019's Joker with his made-up relationship with Zazie Beetz's Sophie among other other fantasy-based scenarios. It'll be interesting to see, then, if all is as it appears when it comes to his burgeoning romance with Quinzel as Joker 2's story plays out.

What does Folie à Deux mean?

Joker and Harleen Quinzel dance in a promo image for Joker: Folie a Deux

Joker: Folie à Deux is an apt title for Fleck and Quinzel's relationship. (Image credit: Warner Bros. Pictures)

It's French for "folly of two", which is an apt decription for Fleck and Quinzel's likely tragic (we're speculating here, FYI) relationship. It's a term that's also used in psychology circles to characterize a shared delusional disorder, which typically sees hallucinations passed between two individuals, which Fleck and Quinzel are sure to engage in throughout Joker 2's runtime.

What song is used in Joker: Folie à Deux's trailer?

Arthur Fleck wears his signature makeup and a blue suit in a jazz club in Joker 2

"Play it for me one more time, guys." (Image credit: Warner Bros. Pictures)

That'll be a cover of Jackie DeShannon's 'What The World Needs Is Love', which feels like an apt choice for a movie whose dual protagonists – Phoenix's Fleck and Lady Gaga's Quinzel – have been starved of true affection throughout their lives. It's why they'll likely be drawn to one another in Joker 2 as these two emotionally and psychological damaged individuals seek comfort in a kindred spirit.

Who else is part of Joker 2's cast?

Steve Coogan's psychiatrist talks to Arthur Fleck in Joker 2

Steve Coogan is confirmed to be part of Joker 2's supporting cast. (Image credit: Warner Bros. Pictures)

So far, Warner Bros. has only confirmed that Phoenix and Lady Gaga will appear in the film. However, Joker 2's first trailer also reveals that Steve Coogan – best known as satirized media personality Alan Partridge – will play a supporting role as Fleck's new psychiatrist. We see him chatting to Fleck on a couple of occasions in the teaser, but we don't know the identity of his character just yet.

As for other actors who are expected to appear – again, Warner Bros. hasn't confirmed any of these individuals will feature – The Hollywood Reporter suggests Brendan Gleeson (The Banshees of Inisherin), Catherine Keener (Get Out), and Jacob Lofland (The Maze Runner) are part of the film's roster. Deadline has also claimed that Harry Lawtey (Industry) will show up and that Beetz might reprise her role as Sophie from the 2019 original.

When is Joker: Folie à Deux's release date?

Arthur Fleck looks up to the rain-filled sky as he's flanked by two prison guards in Joker 2

October 2024 isn't too far away now, everyone. (Image credit: Warner Bros. Pictures)

Joker: Folie à Deux will launch exclusively in theaters worldwide on October 4, 2024. Funnily enough, as long as it keeps that release date, it'll be five years to the date since Joker made its theatrical debut, before it went on to make over $1 billion globally and land multiple prizes on the 2020 awards circuit.

Is Joker 2 part of James Gunn's DC Cinematic Universe?

Robert Pattinson stars as the Dark Knight in The Batman film

The Batman's universe also falls under the DC Elseworlds banner. (Image credit: Jonathan Olley/Warner Bros.)

No – well, it's not part of the DCU Chapter One lineup, anyway. As we mentioned earlier, Joker 2 falls under the DC Elseworlds banner. Essentially, it'll be part of a collection of films and TV shows that take place in alternate universes that exist independent of James Gunn and Peter Safran's DCU

Another example of DC projects that'll be part of the Elseworlds brand is Matt Reeves' The Batman universe. It'll get its first spinoff later this year with The Penguin, a limited series that'll air on Max (US), Sky Atlantic (UK), and Foxtel (Australia). Then, in October 2026, The Batman Part II will fly into theaters.

We don't know if other DC Elseworlds productions are in the works, but there's plenty of movement on the DCU Chapter One front. James Gunn's Superman movie is currently being filmed, while production is expected to ramp up on Peacemaker season 2 and Supergirl: Woman of Tomorrow before 2024 ends. The DCU's first official project – an R-rated animated show called Creature Commandos – is also set to debut sometime this year.

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Senior Entertainment Reporter

As TechRadar's senior entertainment reporter, Tom covers all of the latest movies, TV shows, and streaming service news that you need to know about. You'll regularly find him writing about the Marvel Cinematic Universe, Star Wars, Netflix, Prime Video, Disney Plus, and many other topics of interest.

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