Zack Snyder's Justice LeagueSave

The film opens with Superman dying. The very first sound is Superman's death-scream from Batman v Superman: Dawn of Justice (2016), and the very first image is the slow-motion shockwave of that scream traveling outward across the Earth — visualisizd as a ripple of mourning that wakes up the three Mother Boxes hidden in the Atlantean trench, the Amazonian temple, and the underground Star Labs vault. Snyder's opening conceit is that Superman's death is what activates the inciting incident; his death changes the global frequency, and the Boxes detect that the planet's defender is gone.

Steppenwolf (Ciarán Hinds) arrives on Earth. Snyder's Steppenwolf is unrecognisable from Whedon's — armored in shifting bladework rather than smooth bronze, taller, more demonic in silhouette, and deeply terrified of his master Darkseid. Steppenwolf has been exiled from Apokolips for an unspecified betrayal and must capture 50,000 worlds to redeem himself. Earth is the world he has been searching for: it was the first world that ever rejected Darkseid, in a war Snyder shows in extended flashback featuring the Old Gods, the Amazons led by Hippolyta, the Atlanteans, men of Earth led by an unidentified king — and, in the film's deepest cut, a Green Lantern of the original DC Universe, killed mid-battle.

Bruce Wayne (Ben Affleck) is recruiting. He has met Aquaman / Arthur Curry (Jason Momoa) once already; he has Diana Prince / Wonder Woman (Gal Gadot) helping him; he has tried and failed to recruit the Flash / Barry Allen (Ezra Miller) at the Central City café where Barry has just stopped a Bridget Cabot armed robbery (the Iris West rescue sequence Whedon cut entirely). Bruce's hardest recruit is Victor Stone / Cyborg (Ray Fisher), a former Gotham City University football star who survived a car crash that killed his mother only because his scientist father Silas Stone (Joe Morton) fused him to a Mother Box. Victor refuses to meet Bruce. Diana is the one who eventually breaks through to Victor's mother's grave.

Steppenwolf attacks Themyscira to take the first Mother Box. The Amazonian battle — shot for the original cut but cut entirely from Whedon's version — runs approximately fifteen minutes and is the film's first true action set-piece. Hippolyta (Connie Nielsen) leads the defense; the Amazons die in waves; Phillipus (Ann Ogbomo) is killed leading a chain-relay attempting to delay Steppenwolf. Hippolyta survives by activating the warning-arrow ceremony, lighting the bonfire on Themyscira that lets Diana know in London that the Box has been taken. The arrow ceremony is shot with the same color grading as Diana's bonfire-lighting in the 2017 Wonder Woman film.

Steppenwolf moves on to Atlantis. Aquaman intervenes — fighting Steppenwolf alone in an underwater current that Mera (Amber Heard) is forced to use her hydrokinesis to slow. Steppenwolf wounds Aquaman, takes the second Box, and escapes. Arthur, bleeding into the trench, is rescued by Vulko (Willem Dafoe) — Vulko's Snyder-cut presence sets up Vulko's role in James Wan's Aquaman (2018) and is one of the film's longest stretches of Atlantean worldbuilding. Mera and Arthur have a quiet moment on the surface afterward in which Mera asks Arthur whether he intends to keep running from his throne; Arthur, half-conscious, doesn't answer.

Bruce, Diana, Barry, and a newly-recruited Victor convene at Bruce's hangar in Gotham. Bruce reveals that he has known about the third Mother Box's location — the underground Star Labs vault where Silas Stone has been hiding it — for months. Victor is forced to confront his father directly for the first time since the accident. Their scene, which Whedon's cut compressed to 30 seconds, runs nearly six minutes in Snyder's version: Victor accuses his father of saving his life only out of guilt, Silas accuses Victor of refusing to live with what he has become, and the conversation ends with Silas committing to extract the Box from his own facility despite the risk.

The team's first encounter with Steppenwolf at Star Labs is a route. Steppenwolf is faster, stronger, and more battle-tested than any of them, and he takes the third Box. Silas Stone sacrifices himself to mark the Box's energy with a beacon Cyborg can track. The team is left with no Boxes and no Superman. Bruce, in the film's lowest moment, makes the call: they will use the Boxes' own energy — which they no longer possess — and the same Kryptonian Genesis Chamber technology Lex Luthor used to create Doomsday in BvS to resurrect Superman.

Superman is resurrected. Henry Cavill returns in the iconic black Kryptonian suit (which is comic-accurate to Dan Jurgens's 1993 'Funeral for a Friend' Death of Superman arc — the black suit signified Superman's mourning of his own death and was a major plot point). The black-suit Superman fights the Justice League first; Lois Lane (Amy Adams) is the one who calms him; he and Lois have a quiet farmhouse scene in Smallville with Martha Kent (Diane Lane) before Clark agrees to join the team for the final battle.

Steppenwolf, now in possession of all three Boxes, retreats to the Pozharnov nuclear-reactor site in Russia — a long-abandoned Chernobyl-adjacent facility he has converted into a Unity ritual altar. The team assembles outside Pozharnov for the climactic battle. The action is structured as four parallel fights: Aquaman and Wonder Woman versus Steppenwolf's parademon vanguard, Cyborg jacking into the Mother Boxes to disrupt the Unity, Barry running back in time to undo a fatal explosion, and Superman arriving late but tipping the team toward victory.

Steppenwolf is killed. Cyborg disrupts the Unity. Superman delivers the killing blow, and Wonder Woman decapitates the body — sending Steppenwolf's head through a Boom Tube directly to Darkseid's throne on Apokolips. The sequence is shot for maximum brutality and is one of the goriest sequences in any DC film. Darkseid (Ray Porter), who has been searching for Earth for three thousand years without success, finally identifies the planet through Steppenwolf's severed head. Earth is on his hit list.

The film could end here. Snyder, instead, devotes its final 30 minutes to a five-part epilogue. Part one: Bruce, Diana, Aquaman, the Flash, Cyborg, and Superman regroup at the Wayne Manor lakehouse. Bruce gives Diana a portrait of her father; he tells Aquaman the team will respect his anonymity; he offers Barry a job he isn't sure Barry is ready for. Part two: the Kent farm, where Clark and Lois reveal she is pregnant. Part three: Victor returns to Silas's lab and listens, alone, to the audio note his father left him. Part four: Lex Luthor (Jesse Eisenberg) escapes Arkham on a yacht and tells Slade Wilson / Deathstroke (Joe Manganiello) Batman's identity, setting up a film that never got made.

Part five — the Knightmare sequence — is the film's most-discussed coda. Bruce, in a Mad-Max-esque post-apocalyptic future, leads a small resistance through a ruined Metropolis: Mera, Cyborg, Flash, Deathstroke, and the Joker. Jared Leto's Joker — completely reworked from his Suicide Squad (2016) appearance, now with a low-key chemical-burn face design — has a five-minute conversation with Bruce that is the highlight of the entire epilogue. Joker has, in this timeline, killed Robin. Bruce has, in this timeline, killed Joker's lover (heavily implied to be Harley Quinn). The two men negotiate a temporary truce because Superman, controlled by Darkseid's Anti-Life Equation, is about to descend on them.

Bruce wakes up. The Knightmare was a vision — sent via Mother Box energy by the Martian Manhunter J'onn J'onzz, who reveals himself in the film's final scene. Harry Lennix's General Calvin Swanwick — who has appeared in every Snyder DCEU film since Man of Steel (2013) — finally pulls back his disguise to reveal he has been J'onn J'onzz the whole time. He offers Bruce membership in a wider cosmic alliance. The film cuts to black on Bruce's face as he absorbs that the universe is wider than he thought.

Zack Snyder's Justice League released directly to HBO Max on March 18, 2021, after a three-year fan campaign (the #ReleaseTheSnyderCut movement). The four-hour, sixteen-minute film was presented in 4:3 IMAX aspect ratio with Snyder's preferred desaturated color palette. Warner Bros. spent an estimated $70 million on post-production reshoots and VFX completion to finish the cut to Snyder's specifications. The film is considered the most prominent example of fan-driven director's-cut releases in modern Hollywood history, and despite Snyder's sequel plans being publicly canceled, the cut has been preserved as DC's canonical Snyderverse finale.