- "Your father sacrificed himself to mark that box. We have to get back to my lab and use the satellite to scan the earth for thermal anomalies."
"I'm already on it.
"I'm sorry, you have a satellite?"
"I have six."
"Let's go find this son of a bitch."
- ―Bruce Wayne, Victor Stone, and Barry Allen[src]
Now with all three Mother Boxes in his possession, Steppenwolf decided that it was time to seal the Earth's fate via terraforming it like countless other planets under the orders of Darkseid's Elite. Doing so would redeem Steppenwolf for his betrayal of Darkseid. Steppenwolf and his Parademons went to Pozharnov, Russia and once there, they decided to use a decommissioned nuclear plant as their base of operations for the Unity.
Combat in the Fields
- "I'm gonna take out that tower and knock down that shield dome. Whatever you see, stick to the plan. Its why I brought you together."
- ―Batman to the Justice League[src]
As the Justice League arrived to Pozharnov and gathered to face Steppenwolf and the Parademons, Batman informed the group that he's going to destroy the tower which had the force field around Pozharnov, where he will get them inside as soon as possible. Notably, Steppenwolf watched the Mother Boxes form the Unity as he notified the Parademons of the League to let them come and battle him.
Batman piloted the Flying Fox, with the Batmobile inside, blasted missiles onto the force field to get inside and blasted more onto the tower that made the force field dome, so he successfully opened the whole shield.
Crash-landing to the ground, Batman quickly released the Batmobile to get enough time to drive onto the road, when the Flying Fox got destroyed. Batman then attempted to get the attention of the Parademons, which worked, and some of them chased the Batmobile. They then attacked the Batmobile, ripped off one of the guns that it had an opening up the car before Wonder Woman and the rest of the League saved Batman. Aquaman jumped on the Batmobile before getting attacked by Parademons, which lead Cyborg to save him and throw him to the other Parademons. The Batmobile got knocked over and destroyed, which Batman ejected from the vehicle, used his grapple to swing across, and took out some Parademons who were firing large, cannon-like weapons at the team.
Battle with Steppenwolf
- "Tell me, Amazon... Why did you abandon your own sisters, only to cast your lot with these creatures, clinging to their puny lives? You weren't there to protect them from me. And, sadly, you could have."
- ―Steppenwolf to Wonder Woman[src]
The trio of Aquaman, Wonder Woman, and Cyborg personally took on Steppenwolf, who fought fiercely. Cyborg then split off to work on separating the Mother Boxes while Flash built up a charge to get him inside and weaken the boxes from within.
Eventually, Superman found the League at a nuclear facility in Pozharnov, Russia. Wearing his new black and silver suit, he encountered Steppenwolf and attacked him using both punches and heat vision, and in the process destroyed his axe, giving Cyborg and Flash time to separate the Unity. He kept on him until Cyborg needed him to help him separate the boxes.
Separating the Mother Boxes and Flash's Time Reversal
- "Okay... Just gotta go faster than the speed of light, far beyond the speed of light, you gotta break the rule, Barry, and you gotta do it now!"
Though Steppenwolf was beaten by Superman, the Unity still synchonized and the world was scorching, with a Boom Tube opening to Apokolips to give the world to Darkseid. Injured by a Parademon's shot, Flash ran out of time to send Cyborg into the Unity. Flash remembered that if he ran faster than light, he could go back to before the unity occurred and stop it. He did so, even running as the world was rebuilding, and was able to then deliver the charge to Cyborg, who entered the Unity. The boxes took the form of his deceased father Silas Stone, his also deceased mother Elinore Stone, and himself, whole and with no cybernetic parts. They invited him to go with them, and "be whole" and "not alone anymore". Cyborg saw through this veil and illusion the box created to confuse him, and he destabilized the boxes. He then called Superman over to help him separate the boxes, and they did so.
Enraged by the Justice League's separation of the Unity, Steppenwolf attempts to fight them, but is stabbed by Aquaman and then beheaded by Wonder Woman, and Steppenwolf's head falls through the Boom Tube, where it is stepped on by Darkseid before it closes.
The World's Greatest Heroes
In the aftermath, the heroes all go their separate ways, but are still bonded under the new Justice League.
Barry Allen gets a job in a crime lab, Ryan Choi acquires the Kryptonian ship and becomes the Director of Nanotechnology, Bruce, Diana, and Alfred begin work on turning Wayne Manor into the Hall of Justice, while Bruce still returns to Gotham to fight crime, and Clark still continues work as Superman.
On a certain shore, Arthur bade farewell to Vulko and Mera, telling them that he was off to see his father. He then hitched a ride with a man. At some point, Arthur Curry arrived at the Amnesty Bay lighthouse early before dawn to await his father. While there, he bragged to Topo about having helped save the world.