First Joker 2 trailer sees Joaquin Phoenix and Lady Gaga on a weird and wonderful musical adventure

The first trailer for Joker 2 is here – and it looks like the dreamiest, most unhinged adventure.

In the brief clip, which can be viewed above, Arthur Fleck and Harley Quinn meet in Arkham Asylum. But instead of Harley being the Joker's psychiatrist (as per the comics), she appears to be a fellow inmate – and one who seems to admire Arthur, telling him, "I'm nobody. I haven't done anything with my life like you have."

Though we don't get a proper glimpse at a musical number, we do hear an off-camera voice tease the film's jukebox musical genre: "We use music to make us whole, to balance the fractures within ourselves." As the Joker and Harley fall in love, we see a montage of technicolor clips with that Old Hollywood vibe. At one point, the two are dancing on a rooftop with the scene lit in a way that reminds us of Ryan Gosling and Emma Stone dancing in La La Land. The dreamy vibes will almost make you forget that you're watching two unwell supervillains fall in love inside an asylum.

The film stars Lady Gaga as Harley Quinn, with Joaquin Phoenix returning as Arthur Fleck, AKA the Joker himself. Filling out the cast are Catherine Keener, Brendan Gleeson, Zazie Beetz (returning from the first film), and Steve Coogan. Todd Phillips returns to direct.

So far, every official look at Joker 2, which is officially titled Joker: Folie à Deux, has had a pretty creepy atmosphere. A recent poster saw Harley and Joker dressed in their best, mid-ballroom dance, in the murky light of what looks to be Arkham.

Interestingly enough, the film has been rated R for "some strong violence, language throughout, some sexuality, and brief full nudity."

While Joker 2 is a DC film, it's not arriving as part of DCU Chapter One: Gods and Monsters. Instead, it's part of its own Elseworlds universe (meaning it's not connected to Matt Reeves's Batverse, either).

Joker: Folie à Deux arrives in theaters this October 4. In the meantime, check out our guide to all the upcoming major movie release dates for everything else the year has in store.