In Joker: Folie à Deux, Lady Gaga stars as Harley Quinn opposite Joaquin Phoenix’s Arthur Fleck/Joker. The film—which is part jukebox musical and part crime drama—is the sequel to the 2019 blockbuster hit Joker, which earned Phoenix a Best Actor Oscar.

The movie, where she stars alongside Joaquin Phoenix as Lee Quinzel, premieres in theaters on October 4.

Lady Gaga hit the red carpet in London alongside her fiancé, Michael Polansky, on Wednesday, September 25, to promote new movie Joker: Folie à Deux. The "Die With a Smile" singer wore a vibrant, floor-length red gown custom-made by Celine by Hedi Slimane to the premiere in London's Leicester Square.

Folie à Deux companion album Harlequin dropped on Friday (September 27), and it shot right to No. 1 on iTunes, becoming an instant bestseller.

Pop star and actress Lady Gaga says her surprise "Joker" sequel companion album will feature new songs she wrote for the movie and the record. The Grammy and Oscar-winner announced the 13-track album "Harlequin" on Tuesday,

Lady Gaga brings the drama to the Los Angeles premiere of 'Joker: Folie à Deux.' The singer donned an all-black Celine dress with exaggerated sleeves and cape while on the red carpet at the TLC Chinese Theatre.

Harlequin” is a companion album for the film, in which Gaga stars as Lee, also better known as the unhinged villain Harley Quinn.

The Oscar-winning singer stars opposite Joaquin Phoenix in the upcoming sequel as the disturbed lover of his titular Batman villain.