Steppenwolf's mission is to harvest planets with a machine that drains natural resources and beams them up to Apokolips through a portal created by three ancient Mother Boxes. He attempts to harvest Earth in pre-historic times, but is defeated due to an unexpected alliance between the amazons, the atlanteans and Green Lantern Abin Sur to defend the humans. The Mother Boxes are left behind and split among the three kingdoms.
On present day, Bruce Wayne arrives on Amnesty Bay to recruit Aquaman to his team, but Aquaman refuses. In London, Wonder Woman foils a hostage crisis, then receives a message from Hyppolita asking for help. She arrives on Themyscira just as Steppenwolf returns to Earth and reclaims the Amazons' Mother Box. Alfred has been monitoring alien activity on Earth and learned that several scientists have been kidnapped by Parademons.
Steppenwolf attacks Atlantis and steals their Mother Box. Aquaman attempts to stop him, but fails. Wonder Woman then returns to Gotham to ask Batman for help. Batman recruits the Flash, while Wonder Woman approaches Cyborg, who refuses. While Cyborg is away, his father Silas Stone is captured by the Parademons and the humans' Mother Box is also stolen. Cyborg joins the team as they meet Commissioner James Gordon, who has found the Parademons' nest in an abandoned tunnel between Metropolis and Gotham.
