Plot

Steppenwolf and his Parademons return after eons to capture Earth. However, Batman seeks the help of Wonder Woman to recruit and assemble Flash, Cyborg and Aquaman to fight the powerful new enemy.

Fueled by his restored faith in humanity and inspired by Superman's selfless act, Bruce Wayne enlists the help of his newfound ally, Diana Prince, to face an even greater enemy. Together, Batman and Wonder Woman work quickly to find and recruit a team of meta-humans to stand against this newly awakened threat. But despite the formation of this unprecedented league of heroes-Batman, Wonder Woman, Aquaman, Cyborg and The Flash-it may already be too late to save the planet from an assault of catastrophic proportions.—ahmetkozan

When the evil and powerful Steppenwolf returns to Earth with his demons after the death of Superman, he retrieves the Mother Box from The Paradise Island. Queen Hippolyta warns her daughter Diana Prince about the menace to the planet and the Wonder Woman meets Batman to discuss how to defend Earth. Meanwhile Steppenwolf retrieves the second Mother Box from Atlantis and Batman and Wonder Woman team up with The Flash, Aquaman and Cyborg, with the support of Alfred, to protect the last Mother Box entrusted to humans. But Batman concludes that they do not have enough power to save the world and proposes to use the power of the Box to revive Superman despite the risks. Will his plan work?—Claudio Carvalho, Rio de Janeiro, Brazil

Thousands of years ago, Steppenwolf (Ciarán Hinds) and his army of Parademons attempt to conquer Earth through the combined energies of three Mother Boxes. They are foiled by a unified army that included the Olympian Gods, Amazons, Atlanteans, Mankind, and Green Lanterns. After repelling Steppenwolf's army, the Mother Boxes are separated and hidden in locations around the planet. Anyone who fell in battle to Steppenwolf would be reborn as Parademons. The Amazons kept one of the Boxes, the Atlanteans kept another, while the third was kept hidden in secrecy by humankind so that nobody may be tempted to harness its power.

In the present, the world is in mourning after the death of Superman (Henry Cavill). Martha Kent (Diane Lane) has moved away from her rural home in Smallville while Lois Lane (Amy Adams) feels more alone. Superman's death triggers the Mother Boxes to reactivate and Steppenwolf's return to Earth in an effort to regain favor with his master, Darkseid. Steppenwolf aims to gather the Boxes to form "The Unity", which would instantly devastate Earth and Terraform it into a copy of his home world.

Meanwhile, a man (Holt McCallany) on a rooftop has just committed a robbery. He sees Bruce Wayne/Batman (Ben Affleck) perched on a gargoyle before he leaps over and fights the man. Batman dangles the man over a ledge, using the man's fear to lure out a strange, winged creature. Batman fights the monster until he traps it in a net. The creature explodes moments later, leaving behind three boxes burnt on the wall. Alfred (Jeremy Irons) sees this through the monitor. He tells Batman it's time to round up his team.

In London, a team of robbers stage a heist in a bank, holding the bank's customers as hostages. Standing atop a statue of the Greek goddess Themis (Lady Justice) Diana Prince/Wonder Woman (Gal Gadot) leaps down to stop them. The leader of the robbers plans to use a bomb to destroy nearby technology and bring the city back to the Dark Ages, but Wonder Woman fights back and throws the bomb into the sky as it explodes. The leader then tries to shoot all the hostages; Wonder Woman runs and deflects all the bullets with her gauntlets. She then clashes the gauntlets together to defeat the leader.

On Themyscira, the Amazons are guarding a cube known as a Mother Box. The cube has been pulsating with energy recently, reactivated from an unknown source. A beam comes down from the sky and a swarm of Parademons descend with their leader, Steppenwolf. He attempts to take the Mother Box, prompting the Amazons to fight back. Steppenwolf and his Parademons force the fight outside the temple where Queen Hippolyta (Connie Nielsen) tries to keep the box from their enemy in a furious chase across the countryside. Steppenwolf proves to be too much for the Amazons and succeeds in taking the box back with him. This prompts Queen Hippolyta (Connie Nielsen) to warn her daughter Diana Prince (Gal Gadot) of Steppenwolf's return by lighting the invasion fire.

Prince joins Bruce Wayne (Ben Affleck) in his attempt to unite other meta-humans to their cause, with Wayne going after Arthur Curry and Barry Allen, while Prince tries to locate Victor Stone.

The two of them fail to persuade Curry / Aquaman (Jason Momoa) the heir to the throne of the undersea nation of Atlantis. His meta-human aquatic abilities and superhuman physical attributes originate from his Atlantean physiology and Stone / Cyborg (Ray Fisher) a former college athlete who, after being Cybernetically reconstructed after a nearly fatal car accident, has powers that allow him to fly, turn his arms into cannons, and to manipulate technology, but manage to recruit an enthusiastic Allen / Flash (Ezra Miller) a Central City University student, who can move at superhuman speeds due to his ability to tap into the Speed Force onto the team. Barry visits his father Henry Allen (Billy Crudup) in prison after he was locked up for allegedly murdering his wife when Barry was a child. Henry wants Barry to live his own life and to stop visiting him because he doesn't have any hope that he will ever be freed.

At Star Labs, Silas Stone (Joe Morton) is leaving his job and goes home to Victor. Victor is hiding after everyone thought he died, and he is worried that his new appearance will have everyone see him as a monster. He also sadly remarks that his enhanced networking power bombards him constantly with knowledge of the entire world and that it feels overwhelming. His father pleads with him to hold on and that his powers will be useful. Stone later joins the team after his father Silas is kidnapped, along with several other S.T.A.R. Labs employees, by Steppenwolf seeking to acquire the Mother Box from them.

In a remote region of Russia, Parademons have descended on the nuclear power plant. Inside one of the cooling towers, Steppenwolf places the cube he'd stolen from the Amazonians in a stone monolith. Strange, thick roots suddenly emerge from the ground and spread to the surrounding area. Steppenwolf gloats that the Unity is at hand, and he will take his place among the new gods and a being he calls "Darkseid".

Meanwhile, Steppenwolf attacks Atlantis to retrieve the next Mother Box, forcing Curry to take action. Mera (Amber Heard) tries to intervene as Arthur arrives, but the Mother Box is gone.

The team receives intel from Commissioner James Gordon (J. K. Simmons) leading them to Steppenwolf's army, based in an abandoned facility under Gotham Harbor. Cyborg initiates the attack against Steppenwolf while The Flash, scared at first to get involved in combat but inspired by Batman, takes Steppenwolf's hostages to safety. The Flash rejoins Wonder Woman and Cyborg as they battle the Parademons while Batman uses his Nightcrawler to battle the Parademons. When Cyborg fires a missile from the Nightcrawler Steppenwolf, he easily catches it and aims it at the tunnel wall. Water from Gotham City Harbor floods in.

Although the group manages to rescue the kidnapped employees, the facility is flooded during combat, which traps the team until Curry helps delay the flood so they can escape. The team escapes in the Nightcrawler.

Stone retrieves the last Mother Box, which he had hidden, for the group to analyze. Stone reveals that his father used the Mother Box to rebuild Stone's body after an accident almost cost him his life. Wayne decides to use the Mother Box to resurrect Superman, not only to help them fight off Steppenwolf's army, but also to restore hope to mankind. Prince and Curry are hesitant about the idea, but Wayne forms a secret contingency plan in case Superman returns as a nemesis. Diana disagrees with the plan for fear that Superman may come back the way Zod came back as Doomsday.

Clark Kent's body is exhumed and placed in the incubation waters of the Kryptonian ship alongside the Mother Box, which in turn activates and successfully resurrects Superman. The Flash devises a plan to charge the field as he runs from a distance to build a stronger charge. It works and Superman comes back to life, immediately rocketing out of the ship, and the others go after him.

However, Superman's memories have not returned, and he attacks the group after Stone accidentally launches a projectile at him. On the verge of being killed by Superman, Batman enacts his contingency plan which is Lois Lane (Amy Adams). Superman calms down and leaves with Lois to his family home in Smallville, where he reflects and tries to recover his memories. Distracted by the fight with Superman, the team doesn't realize that Steppenwolf has taken the last Mother Box from the ship.

In Russia, Steppenwolf brings all the Boxes together to begin The Unity. Everything around him starts to burn and decay. More of the huge roots burst from the ground, destroying anything in their path.

Without Superman to aid them, the five heroes travel to a village in Russia where Steppenwolf aims to unite the Mother boxes once again and remake Earth. The team fights their way through the Parademons to reach Steppenwolf, although they are unable to distract him enough for Stone to separate the Mother boxes. The League is able to kill many of the Parademons and they advance to Steppenwolf and the Motherboxes. Communicating with Alfred, Batman sends The Flash out to rescue the family from the house.

Superman arrives and assists Allen in evacuating the city, as well as Stone in separating the Mother Boxes. Together, Superman and Cyborg pull the Boxes apart, stopping the transformation process. Enraged, Steppenwolf tries to finish them off himself, but Superman uses his ice breath to freeze Steppenwolf's ax, allowing Diana to shatter it with her sword. Now weakened and bewildered, the Parademons sense Steppenwolf's fear and begin to tear him apart as they are sent back to their world.

In the aftermath of the battle, Wayne and Prince agree to rebuild Wayne Manor as a base of operations for the team, with additional space for more potential heroes. Prince steps back into the public spotlight as a hero, Allen acquires a job in Central City's police department, impressing his father, Stone continues to explore and enhance his abilities with his father in S.T.A.R. Labs, Curry returns to Atlantis, and Superman resumes his life as reporter Clark Kent.

Superman and The Flash start a race to see who is faster, with a bet placed that if The Flash loses, he has to invite the others to brunch, and if he wins, he gets to tell everyone he beat Superman. Lex Luthor has escaped from Arkham Asylum and recruits Slade Wilson/Deathstroke (Joe Manganiello) to form their own league.