A brilliant Japanese industrialist is kidnapped and replaced with a robot by the forces of evil. A mysterious island appears. Aquaman is attacked by a robot.The evil Darkseid's latest project involves the capture and takeover of Star City, a gigantic orbiting earth colony. To this end, he replaces the satellite's kidnapped inventor Mr. Moko with a robot lookalike that even fools Moko's daughter, Kiri. Meanwhile, Batman, Firestorm and Samurai must steer clear of Darkseid's minions Kalibak and DeSaad and their robot army, long enough to allow Superman, Wonder Woman and Aquaman to seek out and destroy the control equipment hidden in Darkseid's headquarters!