Here's the story behind the jaw-dropping cameo in 'Black Adam' (spoilers!)

Warning: This post contains major spoilers for Black Adam and the future of the DC Extended Universe.

Talk about a super surprise for DC Extended Universe fans. A mid-credits scene featured in Dwayne Johnson's maiden flight as anti-hero Black Adam officially brings back the big blue boy scout who laid the foundation for the current DCEU nearly a decade ago. Henry Cavill's last son of Krypton comes face-to-face with Johnson's champion of Kahndaq in the minute-long sequence, which sets the stage for not only a long-awaited standalone sequel to 2013's Man of Steel, but also a big-screen bout between Superman and Black Adam.

Although it was shot in secrecy, the mid-credits scene leaked days before the film's release, and DC is leaning into the hype with cheeky stunts like this Twitter chat between the Man in Black and the Man of Steel.

The sequence picks up in the immediate aftermath of Teth-Adam's violent re-entry into the present day after a 5,000-year slumber. Having saved his native home from the threat of Sabbac and his demon army, Adam is trying to figure out his place in the world. And he's not the only one: ARGUS director and Task Force X (aka the Suicide Squad) mastermind Amanda Waller (Viola Davis) has been closely monitoring Earth's newest super-strong, nigh-invulnerable resident, whose mean streak could mean serious trouble.

Having already failed to take the freshly rechristened Black Adam off the DCEU chess board by locking him up in an underwater prison, Waller is trying a different tactic: treating Kahndaq as his jail. But the god-like warrior — whose powers come from the all-powerful wizard Shazam — isn't interested in staying put. "No one on this world is powerful enough to stop me," he tells Waller, a boast that he's already backed up by defeating the various members of the Justice Society, including Hawkman (Aldis Hodge) and Doctor Fate (Pierce Brosnan), in head-to-head combat. "I can call in a favor from people who aren't of this world," she replies calmly.

Hey, Man of Steel! That's your cue. A sudden dust storm kicks up around Black Adam, out of which strides a shadowy figure. "It's been awhile since anyone's made the world this nervous," the caped shape says he walks into view, eventually revealing Cavill in full Superman gear. "Black Adam, we should talk." Based on the look on Black Adam's face, though, he's more in the mood for a good old-fashioned punch-up.

Let's all pause and take stock of the long road that led to Cavill finally suiting up as Superman again after a five-year absence from any DCEU set. The last time that the British actor shot scenes in character was for the Joss Whedon-helmed reshoots of 2017's Justice League, which were intended to make a more commercially-viable version of the team-up adventure that was originally directed by Zack Snyder. (Snyder cast Cavill as Superman for Man of Steel and directed him again in 2016's divisive Batman v. Superman: Dawn of Justice.)

After Whedon's Justice League tanked at the box office, Cavill's future in the DCEU seemed in doubt. Although Superman made a cameo in 2019's Shazam!, it was Zachary Levi's stunt double who wore the suit for that appearance. And while Justice League stars like Ben Affleck returned to film additional material for the four-hour Snyder Cut of the film, which premiered on HBO Max last year, all of Cavill's scenes had been completed during the original shoot. In the meantime, the actor moved on to headline the hit Netflix series The Witcher as J.J. Abrams announced plans to develop a separate film that would have introduced a Black Superman.

It's worth noting that Black Adam had been through its own creative maelstrom over the years, with the character's introduction originally earmarked for an earlier version of Shazam! until Johnson used his star power to insist on a solo outing. (Teth-Adam does make a blink-and-you'll-miss-it appearance in the 2019 movie.) And even though Shazam has traditionally been Black Adam's regular foil in the comics, the star always had his sights set on a match-up with DC's main man. (No, not that one.)

According to The Hollywood Reporter, Johnson first pitched bringing Cavill back while filming Black Adam reshoots earlier this year. (Cavill is a client of Johnson's manager and ex-wife, Dany Garcia.) The idea was vetoed by outgoing DC Films President Walter Hamada, who had been a proponent of Abrams's new Superman project. So Johnson appealed directly to the heads of Warner Bros. Pictures, Michael De Luca and Pam Abdy, who gave their blessing. The top-secret scene was filmed in September, a little over a month after DC's presentation at San Diego Comic-Con where many expected Cavill to make an appearance.

Now that these super-bros have officially met, Johnson is no doubt hoping to quickly deliver on the Superman vs. Black Adam film he's been teasing ahead of the movie's release. "We're ushering in a new age of the DC Universe," Johnson declared at San Diego Comic-Con, while artfully dancing around the Superman question. "It was time for a shift and to listen to the fans."

Speaking to Yahoo Entertainment, Johnson elaborated: "I feel this is our opportunity to expand the DC Universe ... you'll see in Black Adam that we acknowledge everyone — Batman, Superman, Wonder Woman, Flash — we acknowledge everybody. There's also some Easter eggs. ... So maybe 'resetting' wasn't a good term, it's expanding."

But as The Hollywood Reporter reports, Warner Bros. also has longer-range plans for Cavill that includes Man of Steel 2, potentially overseen by the actor's Mission Impossible: Fallout director, Christopher McQuarrie. Superman could also be on hand for an appearance in James Gunn's secrecy-shrouded plans for more DCEU films after The Suicide Squad and his hit HBO Max spin-off, Peacemaker (which, like Shazam!, used a stand-in for Cavill in the season's final scene).

At press time, Cavill himself hasn't publicly addressed his return — or his future — in the DCEU. But based on the huge cheers that greeted his appearance in the screening of Black Adam that Yahoo Entertainment attended, he's once again the Man of Tomorrow... today.

Black Adam is currently playing in theaters now.

Watch Dwayne Johnson describe 'Black Adam' as the 'most raging and violent' film he's done: