Bros. set a two-week shoot for Fisher to film what was referred to as a cameo appearance alongside other Justice League actors. Fisher said the studio only offered to pay him a fraction of his traditional salary for reprising the role. In August, Keaton was confirmed to be appearing in the film, and Affleck agreed to reprise his version of Batman. Muschietti explained that the film would be introducing the idea of the multiverse to general audiences by including multiple versions of characters and acknowledging past film franchises based on DC Comics as alternate universes. It was important for Muschietti to include Affleck in the film since his version of Batman is the "baseline" for the DCEU, and he felt the introduction of Keaton's Batman would not work as well without first seeing the Flash's relationship with Affleck's Batman. Affleck chose to return, after saying he had retired from the character, because he would have a smaller role in the film. During the virtual DC FanDome event "Explore the Multiverse" in September 2020, Barbara Muschietti said the film would feature many characters from the DC Universe and the Flash would serve as the bridge between them and their different timelines. She added that the film would be used to restart the continuity of the DCEU without disregarding the events of the prior films. Crudup, who left the film during the changes in directors, entered negotiations to rejoin the project a month later. Clemons' involvement was uncertain at that point. The film's release was pushed back to November 4, 2022, due to further pandemic-related delays, and filming was set to begin in March 2021 in London. Warner Bros. had written Cyborg out of the film by January 2021 after Fisher refused to work on any project that DC Films president Walter Hamada was involved in. Fisher said this was due to Hamada's handling of an investigation into the on-set behavior of Justice League replacement director Joss Whedon. The role of Cyborg was not expected to be recast. Andy and Barbara Muschietti arrived in the United Kingdom to prepare for production, with filming set to begin in April at Warner Bros. Studios, Leavesden, after Miller finished on The Secrets of Dumbledore. In February, construction for sets at Leavesden Studios had begun, Crudup was confirmed to be returning, and Sasha Calle was cast as Supergirl. Calle was chosen from a group of more