In which a door is encountered. 

The members of the Justice League find themselves in the mysterious world of Remnant, de-aged into teenagers and split up from each other. Superman meets Ruby Rose and Yang Xiao Long in Vale, Wonder Woman teams up with Blake Belladonna in Menagerie, Batman works with Weiss Schnee after a conflict in Atlas, and The Flash, Green Lantern, Cyborg, and Vixen wake up in Beacon Academy alongside Jaune Arc, Nora Valkyrie, and Lie Ren.

Team RWBY find themselves remembering events that don't exactly line up with the world they're in, while the Justice League struggles to remember how they wound up in this new world. The two groups team up to find out what happened to them and protect the world from strange Grimm with unusual abilities regarding Dust.