Following Superman's death, Bruce Wayne and Diana Prince work to assemble a team of metahumans to defend Earth against a powerful alien conqueror named Steppenwolf, who seeks to unite three ancient artefacts called Mother Boxes to terraform the planet. The newly formed league — including Aquaman, the Flash, and Cyborg — ultimately determines that resurrecting Superman is their best hope of defeating the threat. The reunited team confronts Steppenwolf in a climactic battle, with the restored Superman proving decisive in turning the tide.