When a peaceful colony on the edge of the galaxy finds itself threatened by the armies of the tyrannical Regent Balisarius, they dispatch Kora, a young woman with a mysterious past, to seek out warriors from neighboring planets to help them take a stand.

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.