10 years after the events of Fallout: Equestria, in the lands surrounding New Pegasus, Stable 112 has been opened to the outside world for almost half a century. Most ponies ignore it though, a few raiders have tried to loot it, but most just vanish. Left behind in Stable 112 was Project Legacy, a secret Stable-tec project built to build a new generation of ponies from genetic material. Now, Rain Runner, a survivor of the project must strike out on her own, and find her own place in the Post-Apocalyptic world.