Production on the sequel film to the 2019 hit starring Joaquin Phoenix as the troubled loner will begin production shortly with a 2024 release date pencilled in.

One of the nation's sweethearts is heading to the DC Universe - sort of. Brendan Gleeson is suiting up for 'Joker: Folie à Deux', the follow-up to Todd Phillips' standalone film.

Gleeson joins the cast in an undisclosed role, but Warner Bros. has yet to comment on the casting. Deadline, however, has received word that the 67-year-old will join the film, which is set to be a musical.

A musical is a far departure from the last time we caught up with Arthur Fleck, played so famously (Oscar-winning famously) by Joaquin Phoenix. Lady Gaga was rumoured to be circling a role in the follow-up film earlier this year, and it was confirmed a number of weeks ago that she had joined the cast.

Although still unconfirmed, the Oscar-winner is believed to be playing Harley Quinn, a character whom anyone familiar with the character will know that Joker has a very tumultuous relationship with. The film's subtitle 'Folie à Deux' refers to a delusional disorder shared between two or more people. It was also recently confirmed that Zazie Beetz will reprise her role as Arthur's neighbour, Sophie.

Brendan Gleeson joining 'Joker: Folie à Deux' will be the first time that the Irish star has a role in a "superhero" film (well, this isn't really a superhero film, but you know what we mean). 'The Guard' and 'Harry Potter' star will appear on our screens very soon for 'The Banshees of Inisherin'.

Director Martin McDonagh'J managed to reunite Gleeson and Colin Farrell for the first time since 'In Bruges', saying he "was always hoping no one else would work with them as a pairing". The film, which is about two lifelong friends whose relationship ends suddenly, is set for release on October 21.

'Joker: Folie à Deux' has a release date of October 4, 2024.