- "It's really cool you guys seem ready to do battle and stuff, but, full transparency, I've never done battle. I've just pushed some people and run away."
"Save one person."
"Uh... which one?"
"Don't talk, don't fight. Get in, get one out."
- ―Batman and Flash[src]
The Justice League received intel from Commissioner James Gordon that the Parademons are traveling underground, which the team goes to find. The team climb up, to find Steppenwolf interrogating the S.T.A.R. Labs employees about the final Mother Box, which Flash gets nervous and tells the team that he hasn't done battle before, which Batman said just save one person.
Steppenwolf then grabs Silas Stone, which Cyborg shoots Steppenwolf and saves his father, then Wonder Woman helps out by attacking the Parademons and taking Steppenwolf to a different part of the factory. While Batman fights the Parademons, Barry goes and save one of the employees. Steppenwolf tells the Parademons that he will deal with Diana alone: Meanwhile, Batman is being attacked by one of the Parademons, then he tells Alfred that he needs the Knightcrawler, which he sent the machine to Bruce.
Flash and Cyborg save all the hostages, which Silas Stone tells Victor that Steppenwolf can not get the final Mother Box. Batman then jumps down into the Knightcrawler and saves Wonder Woman after a Parademon manages to briefly knock her out. The Knightcrawler gets attacked by Steppenwolf, and Barry helps Wonder Woman get her Sword so she can help Batman.
Flash and Wonder Woman get attacked by Steppenwolf and the Parademons before Batman helps her by killing one of the Parademons. Cyborg then falls into the Knightcrawler and hacks into it under his control, which he uses it against Steppenwolf, but fails when Steppenwolf caught a missile and threw it against the wall, which causes the factory to flood and it allowed Steppenwolf to escape.
After the fight with Steppenwolf, Batman meets with Gordon before Arthur shows up and say that Steppenwolf took the Mother Box from Atlantis, then Victor reveals that he is possession of the final Mother Box, which he hid from his father. The team returns to the Batcave which Barry runs around the cave and sits in the Batmobile, before Bruce called for a meeting with the team. Bruce concluded that they should use the Mother Box to bring Superman back to life. He believes that they need Superman to restore hope in humanity. Diana and Arthur are hesitant about the idea, but Bruce forms a secret contingency plan.