Sunset returns through the portal when it opens again, wanting to make amends for the past. However, things get complicatred when she discovers a familiar dark artifact. Lured by a promise of power, can Twilight save her from herself a second time?
Sunset Shimmer finally returns home to Equestria to right her old wrongs, unfortunately the sins of the Human World follow her back and put everypony in Equestria in danger.
Sunset Shimmer was simply enjoying a night indoors with her friends, but the magical energies of the human world which clashed in Rainbow Rocks has caused something unexpected to happen.