An in-movie Joker film inspired by Arthur Fleck is frequently mentioned throughout Joker: Folie a Deux, while never seen in the sequel, was at one point conceived as a trailer, and director Todd Philips, who returned for the successor, even had a name in mind to play Fleck. “Well, Justin Theroux of course,” the director said, speaking an interview with IGN.
Theroux (Beetlejuice 2) famously showed up in a cameo during the first film, starring as actor Ethan Chase, appearing as a guest star on a talk show hosted by Murray Franklin (Robert DeNiro). Fleck would later go on to kill Murray live on the show.
If it had gone ahead, the in-movie trailer brings to mind the in-show satirical trailers and blockbuster films depicted in The Boys. “In fact, I talked to Justin about it,” Philips later explained.
Discussions had reached a point where the team, with Theroux on board, were set to go ahead. “We were going to shoot a trailer at one point,” Philips said. “We just ran out of time.”
Ultimately, neither a mock film nor a trailer to tease said movie has ever seen the light of day, and Theroux does not appear in Joker: Folie a Deux, a sequel that had been rewritten so often, that the writers had to resort to writing on napkins to ensure the ideas were noted down.
Joker: Folie a Deux further stars Brendan Gleeson, Catherine Keener, Zazie Beetz, Harry Lawtey, and Steve Coogan. A sequel to the first Joker film, released in 2019, Joker: Folie a Deux arrived in cinemas on October 4, 2024.