In Warner Bros.’s upcoming The Flash movie, sources confirm that Batman will featured as a cameo role, and Ben Affleck will be returning as the famous crimefighting superhero. Back in January 2019, despite being involved in early development on Matt Reeves’ The Batman, Affleck stepped away from reprising the role in that movie. For this upcoming big screen movie though, Affleck reportedly got the script for The Flash at the end of last week and agreed to board the project.

Affleck won’t be the only Batman in the movie, however. Michael Keaton is set to appear as the Dark Knight from the 1989 Tim Burton film. Regarding Keaton’s returning role, Flash director Andy Muscietti (It, It Chapter Two filmmaker) claims it as a “substantial” part.

The Flash movie, which is planned for release in summer 2022, will feature the hyper, fast-moving hero Barry Allen, played by Ezra Miller, who not only wins every race with his outstanding speed, but can break the bonds of physics to crash into various parallel dimensions, where he’ll encounter slightly different versions of DC’s classic heroes. The Flash is said to be an adaptation of DC’s 2011 Flashpoint series of comic book crossovers.

Muscietti goes in depth in explaining why specifically Affleck’s Batman will be making a comeback. He explains that “he’s a very substantial part of the emotional impact of the movie. The interaction and relationship between Barry and Affleck’s Wayne will bring an emotional level that we haven’t seen before.” He adds that “It’s Barry’s movie, it’s Barry’s story, but their characters are more related than we think. They both lost their mothers to murder, and that’s one of the emotional vessels of the movie. That’s where the Affleck Batman kicks in… His Batman has a dichotomy that is very strong, which is his masculinity—because of the way he looks, and the imposing figure that he has, and his jawline —but he’s also very vulnerable. He knows how to deliver from the inside out, that vulnerability. He just needs a story that allows him to bring that contrast, that balance.”

Muscietti also offers another reason that follows more of the storyline. Miller’s Flash considers him to be the original Dark Knight, the guy he fought alongside in Justice League. Hence, it was necessary to have Affleck’s Batman as a starting point: “He’s the baseline. He’s part of that unaltered state before we jump into Barry’s adventure…There’s a familiarity there.”

Affleck was cast as Batman back in 2013 and had appeared in Batman v Superman: Dawn of Justice and Justice League—and one cameo in Suicide Squad. However, he has never had a standalone movie, although he had previously signed to direct and star in a standalone film called The Batman, but ultimately left the project after saying that its demands were taking too much of a personal toll. Nevertheless, DC fans will get to see Batfleck in action once more.