Lady Gaga is seen bringing the music, dance and a very bad romance to the Joker film sequel in its first trailer.
The singer and actress plays a new version of Harley Quinn in Joker: Folie à Deux opposite Joaquin Phoenix, who won an Oscar for the original movie.
The pair seemingly meet and fall in love in Arkham Asylum before apparently escaping and forming a musical duo.
Director Todd Phillips said it isn't a musical, as had been rumoured, but that music is "an essential element".
Phoenix won an Oscar for best actor for his performance in 2019's Joker.
Here are seven things of note from the sequel's trailer.
Allow YouTube content?
This article contains content provided by Google YouTube. We ask for your permission before anything is loaded, as they may be using cookies and other technologies. You may want to read Google’s cookie policy, external and privacy policy, external before accepting. To view this content choose ‘accept and continue’.
Arthur Fleck (aka Joker) and Harley Quinn's eyes appear to meet as she takes part in a singing group in Arkham Asylum, where he was left at the end of the 2019 film.
Her origin story is as a psychiatrist at the institution who is obsessed with the failed comedian and "crown prince of crime" – but here, she could be a fellow inmate. It's not quite clear which side of the bars she's on.
"It seems to confirm a massive shift in Harley Quinn's origin story," wrote IGN's Alex Stedman, "as it appears to show her as a patient in Arkham Asylum rather than as a psychiatrist".
"Long gone, it seems, are the days of Dr Harleen Quinzel."
But if she is working rather than residing there, that might help explain how she can help him escape.
"Let's get outta here," she whispers, before the pair are seen in a fantasy rooftop dance sequence.
That abruptly cuts to a gritty Gotham City street, where they continue their carefree dance as emergency vehicles rush in the direction of whatever chaos they have just caused.
"We use music to make us whole – to balance the fractures within ourselves," the title character is heard saying in voiceover.
Joker has found a partner in love and crime, but also music. In one clip, they perform as Joker & Harley on a TV show, complete with full band and backing singers.
The trailer is soundtracked by What the World Needs Now Is Love, made famous in 1965 by Jackie DeShannon.
"I like to say it's a movie where music is an essential element," Phillips told CinemaCon on Tuesday, when asked whether this is a musical.
"To me that doesn't veer too far from the first film," he said, adding that in that original film, "Arthur has music in him. He has a grace to him."
Indeed, one of the most famous scenes from the first film was where Joker danced down a flight of stone steps. In the new trailer, Harley is seen walking up those same steps.
In another snippet, she and Joker mimic his original dance as they go down what look like courthouse steps, with cheering crowds on either side.
Thankfully, there's no Gary Glitter music this time.
At another point, Harley, wearing a white wedding dress and veil, dances down an aisle to a chapel, where Joker is waiting in a white suit, apparently accompanied by backing singers as bridesmaids.
This is, however, one of several fantasy sequences that are reminiscent of classic Hollywood movie musicals.
That led one person on X to say it looks like 2016 musical La La Land, but for "people who hear voices".
The British comedian and actor pops up in the trailer as some sort of authority figure who asks Arthur/Joker: "What's changed?"
"I'll tell you what's changed – I'm not alone any more," he replies.
Coogan's appearance led some to hope for a repeat of a line by his most famous character, Alan Partridge, when he declared: "I'm Batman!" Which really would be a plot twist.
After causing mass mayhem, with riots on the streets, an explosion in a packed room with TV cameras (the same studio as their performance?), and Joker and Harley running hand-in-hand out of a flaming building, the trailer ends quietly with Harley apparently visiting Arthur in prison.
Using her red lipstick, she draws a curved line on the glass between them and tells him: "I want to see the real you."
Phoenix's glum face slowly shifts and breaks into a big smile, which aligns with the now out-of-focus lipstick to suddenly become Joker's famous red face paint.
A masterful shot which we hope took several hundred attempts to perfect, rather than having the lipstick digitally added in post-production.
The trailer actually ends with the release date – 10.04.24 – which means it's out TODAY! Hurrah!
Oh, wait. Americans write their days and months the wrong way around. So we'll actually have until 4 October.
Mean Girls, Wicked and Dune 2: Film highlights for 2024
Joaquin Phoenix's unusual Oscar campaign trail
Oscars 2020: Joker leads pack with 11 nominations
Joker sequel reportedly in the works
The Joker: The many faces of Gotham's most wanted
OJ Simpson, NFL star cleared in ‘trial of the century’, dies aged 76
OJ Simpson: His life and the trial that defined it. Video
Biden vows to defend Philippines in the South China Sea
India election: What is at stake in the world's biggest poll?
OJ Simpson: His life and the trial that defined it. Video
'I survived the ferry disaster – but lost 17 of my family'
Weekly quiz: How did 'Hardest Geezer' celebrate the end of his Africa run?
Suicide is on the rise for young Americans. Why?
South Korean leader learns political cost of a spring onion
Arizona pushes abortion to centre stage of 2024
How gang violence gripped a tourist haven
All you need to know for tonight's Bafta Games Awards
Let's banish complicated toilet flushes
Paul Merton talks to Hannah Fry to find out what she would send to Room 101
Why did Vine end up toast?
Sean Farrington investigates what happened to the first ever video app sensation
Remembering an alternative rock legend
6 Music reflects the influences and work of Kurt Cobain, 30 years after his passing
The man who entertained the UK for eight decades
Political writer and broadcaster Steve Richards reminisces on the genius of Bruce Forsyth
© 2024 BBC. The BBC is not responsible for the content of external sites. Read about our approach to external linking.