How The Flash brought to life a Superman that could have been

Warning: This article contains spoilers for The Flash.

Of all the cameos in The Flash — yes, including the return of Michael Keaton's Batman — there's one that consistently elicited the most audible reactions from audiences in early screenings.

It comes towards the very end during a climactic, visual effects-heavy scene: Barry Allen (Ezra Miller) chases his past self to what is referred to as the Chronobowl, which the Flash can reach by moving faster than the speed of light. The Chronobowl is like a visual representation of the timeline, and Barry can travel backwards or forwards in history from this space. After all this tampering with time, however, Barry's reality starts to collide with various other realities in the multiverse.

It's here where audiences get a peek into other alternate timelines of the DC cosmos. There's one reality where actor John Wesley Shipp, who played the Flash in the 1990s CBS series, appears as the speedster. In another reality, there exists actor Adam West's version of Batman, which headlined the 1960s ABC series. In another, there are CG renderings of Christopher Reeve's Superman and Helen Slater's Supergirl. In yet another, we see the George Reeves-era Man of Steel. (Reeves starred in Adventures of Superman in the 1950s.)

But the cameo that had audiences truly freaking out was one that had been leaked weeks prior to the film's release: Nicolas Cage. Cage appears as the Superman of another parallel reality, and it's a version of the hero whose story we never got to see play out on screen.

Here's a quick history refresh: After directing Keaton in his Batman films, director Tim Burton turned his attention to the character of Kal-El. The filmmaker had been developing a movie called Superman Lives for years in the '90s that would have starred Cage as the Man of Steel, with a script written by Kevin Smith. That movie ultimately never happened. EW reported at the time that Warner Bros. was coming off of films like The Postman and Sphere that cost a lot to make but struggled at the box office. Burton has since criticized the heavy studio interference on Superman Lives. "These studios become big corporations and you're having to design these characters for Happy Meals before you design it for the film," he told Howard Stern in 1999.

Superman Lives has since become the stuff of legend, and was chronicled in the 2015 documentary The Death of Superman Lives: What Happened?.

"Part of the idea of the multiverse is presenting these worlds as living together and real," The Flash director Andy Muschietti tells EW in an interview. "So the fact that [Superman Lives] wasn't made, doesn't mean that that doesn't exist somewhere in the multiverse. That was my grease from the beginning of this."

According to producer Barbara Muschietti, Andy's sister, plenty of brainstorming went into which DC figures they wanted to include in the Chronobowl sequence. Among them were Lynda Carter's Wonder Woman, Marlon Brando's Jor-El (Superman's father in 1978's Superman), and Cesar Romero's Joker (in the West-led Batman series). "We had a lot more characters that we had to let go because there just wasn't the time," she said. Then Muschietti blurted out Cage's name. "We were all gobsmacked," Barbara says. "We were like, 'We have to get him!' Immediately we called his agents."

"He did volume-capture because we needed his performance, but in the movie, obviously Superman is younger, so we wanted to portray a Superman that is the age that Superman was in 1996, which is the year where the movie Superman Lives would have come out," Andy Muschietti explains. "We did have to refer to digital enhancement in the aging."

Though there was heavy CGI involved to de-age Cage for the cameo, Barbara confirms, "We shot him in his suit and he looked insane. Amazing."

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