The following post contains SPOILERS for Zack Snyder’s Justice League. So many spoilers.

It was surprising enough that Zack Snyder was able to finish his cut of Justice League at all. But last year, that development got even more shocking when it turned out Snyder was not just finishing the rough cut of the film he’d made before he left the project during production, he was shooting new material for his “Snyder Cut” that would feature Ben Affleck’s Batman, Jared Leto’s Joker, and more.

The specifics of exactly what Snyder was reshooting was never made clear, until Justice League producer Deborah Snyder told Insider in a new interview. The added material is specifically — and only — the epilogue; the “Knightmare” future that will supposedly come to pass in future sequels that, at this point, look like they were never made.

According to Deborah Snyder, this was what Snyder had always wanted to include, but never figured out precisely how before he left Justice League. As she put it:

Zack always felt the ultimate for him was to see Batman and Joker together in a scene. It was something we thought about while working on the movie but couldn’t figure out how it would fit. So when we had this opportunity to do the movie again he said he really wanted to do it.

Interestingly, even though Affleck and Leto are the focus of the scene, the two were never on set together a single time. The entire sequence was filmed over the course of three days, with Affleck, Ray Fisher, Amber Heard, and Joe Manganiello the only members of the cast who actually occupied the same space together. (The Flash star Ezra Miller was working in London on Fantastic Beasts 3, so he was directed over Zoom.)

Given all the logistical problems, the results are pretty seamless — although it’s also clear that Affleck is not in the same shape he was during the original Justice League shoot. That Batman cowl doesn’t fit quite the same way it did a few years ago. Zack Snyder’s Justice League is available now on HBO Max.

Gallery — The Biggest Changes From Justice League to the Snyder Cut:

Warner Bros.

A Totally Different Introduction

Right from the very first moment, you know you’re in for a different Justice League. Whedon’s version begins with a saccharine scene that looks like it was shot on an iPhone, with a bunch of kids asking Superman about what his chest symbol means and how he feels about life on Earth — presumably placed there by the powers that be because otherwise Superman doesn’t appear in the film at all for about an hour. Snyder’s version opens with Superman in a totally different context — in a flashback to his death at the end of Batman v Superman. He howls in slow-motion agony and then his screams travels around the world, activating Mother Boxes and precipitating Steppenwolf’s invasion. One begins with a moment of lightness and hope, the other with the brutal death of the most beloved superhero in history. That sets two very different tones for what’s ahead.

Part of the problem with that Whedon opening scene — and with a lot of his scenes involving Superman — is that when Henry Cavill returned for reshoots, he famously refused to shave off his Mission: Impossible mustache, meaning it had to be digitally (and also awkwardly) erased in every single shot. It’s often very noticeable, and it turns moments that should be deadly serious, like when he threatens Batman with his “Do you bleed? You will,” line from BvS, into complete embarrassments. Superman’s role is almost identical in both cuts; he’s dead, he returns, he fights the Justice League, Lois straightens him out, he saves the day. But getting rid of the digitally erased mustache makes all of that so much better.

Whedon’s cut has a running gag about the Parademons and how they are drawn to fear. Josstice League introduced Batman by having him use a thug as bait to attract a Parademon, so he could capture one and try to understand it. This fear subplot threaded all the way through to the very end of the film, when Steppenwolf is defeated because he gets afraid of the Justice League after Superman returns, and then the Parademons attack him in response. All of that’s gone this time. Now the Parademons are just evil alien minions who do Steppenwolf’s bidding.

Darkseid was like a big unspoken absence at the center of the Whedon Justice League. In DC Comics, Steppenwolf only ever operates as a deputy of Darkseid’s, but for whatever reason, he never actually showed up in the theatrical cut of the movie. It was assumed and implied that Steppenwolf was acting on his behalf, but he was never seen. That’s very much changed in the Snyder Cut, where Darkseid (and DeSaad, another denizen of Apokolips) not only orders around Steppenwolf in the present, but also appears in the place of Steppenwolf in the flashback to the ancient battle scene featuring the Amazons, Atlanteans, and more fending off an alien invasion. Along with all these changes comes a more complicated motivation for Steppenwolf — now he’s not just conquering Earth for poops and giggles, he’s somehow fallen out of favor with Darkseid and decimating our world is his way of getting back in his good graces. (Obviously, Steppenwolf’s design is totally different in Snyder’s cut as well.)

Cyborg’s Backstory Becomes the Actual Story

This shot of a picture frame of Victor Stone with his mom and dad is about as much of Cyborg’s backstory as we ever got in the Justice League theatrical cut. There were oblique references to the accident that killed Victor’s mom and forced his dad, Silas Stone, to experiment on him, but there just wasn’t time to delve too deeply beyond that in a two-hour movie. The four-hour Snyder Cut adds in a ton of material about the character and his family, including flashbacks to the night of the accident, scenes of Victor’s football career prior to his heroic transformation, and a lot of scenes at S.T.A.R. Labs where Silas works.

Danny Elfman’s Score Is Gone

Before he quit the movie, Zack Snyder had hired Junkie XL to do the score for Justice League. (He previously worked on the scores for Snyder’s Man of Steel and Batman v Superman with Hans Zimmer.) After Snyder left, Whedon decided to discard his music and replace him with veteran composer Danny Elfman, who previously worked on superhero movies like Tim Burton’s Batman and Sam Raimi’s Spider-Man. The two scores are very different and give each movie a strikingly different feel. Elfman’s music is much more traditional in its soaring superhero themes; it’s exciting and epic. Junkie XL’s score is much more melancholic, and repeats a lot of the musical motifs from Man of Steel and Batman v Superman, which connects Zack Snyder’s Justice League much more strongly to those earlier films as the conclusion of a cohesive trilogy.

The Justice League Loses (Briefly)

In the Whedon Cut, the return of Superman basically turns Steppenwolf from an insurmountable foe to a total wuss, and from that point the Justice League defeats him handily. In the Snyder Cut, there are a few more complications. Even the arrival of Superman can’t entirely turn the tide. Flash misses his cue to help Cyborg separate the Mother Boxes, which means “The Unity” occurs, and the Earth is completely destroyed. Fortunately for all of us, there’s no sequel money in a movie where the bad guys succeed in erasing all life from the planet, and so the Flash uses his speed powers to run fast enough to reverse time and make it back to Cyborg to separate those darn Mother Boxes. (Yes, Flash uses Superman’s trick from 1978’s Superman to beat the bad guys.)

Superman showing up scares the crap out of Steppenwolf — which in the Whedon Cut means the Parademons smell his fear and are drawn to it. That’s how he’s ultimately beaten; the Parademons swarm all over him, a Boom Tube appears, and all of them are sucked back to who-knows-where in outer space. Snyder goes a very different and far more violent route. This time, the Justice League doesn’t just stop Steppenwolf, they straight-up kill him. Aquaman impales him on his trident and then Wonder Woman beheads him with her sword. Yes, it turns the DC superheroes into vicious killers. But look how nicely they’re working together as a team!

All of the focus on Victor Stone’s backstory pays off, at least on an emotional level, in the scenes where the Justice League revives Superman. Silas Stone winds up with the Mother Box (the Justice League can’t keep their hands on the thing in either cut) but then he’s cornered by Steppenwolf. Silas then sacrifices his life to do some science-y thing to the Mother Box, which tags it with a kind of energy that the Justice League can then track, enabling them to follow Steppenwolf back to his secret lair. In the theatrical Justice League, that scene never happens; Silas never finds the Mother Box, Steppenwolf grabs the unguarded MacGuffin, and the Justice League is magically able to find him without the tag. As a result, Silas survives the film, and Whedon’s epilogue shows Silas and Victor working together on upgrading his cyborg body. The version where Silas dies fits better in Snyder’s themes about lost fathers. (Superman got two dead dads, Batman’s got one, Aquaman’s estranged from his, Flash’s is in prison, and Wonder Woman doesn’t even have one at all.)

The original version of Justice League set up a sequel with a post-credits scene featuring Jesse Eisenberg’s Lex Luthor recruiting Joe Manganiello’s Deathstroke to start their own team of super-villains. That scene still appears in Zack Snyder’s Justice League, but with different dialogue that seems like it was designed to set up Ben Affleck’s solo Batman movie rather than Justice League 2. (Now Luthor’s less intent on starting his own Legion of Doom and more interested in destroying Batman specifically, even spilling Batman’s secret identity to Deathstroke.) Snyder’s film then adds not one but two additional teasers. The first is set in the “Knightmare” future first glimpsed in Batman v Superman: Dawn of Justice, where Superman has turned evil and helped Darkseid conquer the Earth, and Batman leads a ragtag group of surviving heroes and villains against him. Then Bruce Wayne wakes from this “Knightmare” in the present and Martian Manhunter shows up at his window, congratulating him on bringing together the Justice League but warning him that more trouble lies ahead. (Maybe; we’ll see what Warner Bros. has to say about that.)