When the universe's greatest villain returns in a terrifying new form, old adversaries, the Reds and Blues of Blood Gulch, will have to set aside their differences to save the galaxy one last time.

Superman, Batman, Wonder Woman, Flash, Cyborg, Green Lantern and Vixen are transported to the strange world of Remnant and find themselves turned into teenagers. Meanwhile, Remnant heroes Ruby, Weiss, Blake and Yang must combine forces with the Justice League to uncover why their planet has been mysteriously altered before a superpowered Grimm destroys everything.