In this Alternate turn of events, we see how the aftermath of Cozy Glow's villainous acts may have gone differently.
Applejack and Rainbow Dash have been married for some time, and after Cozy Glow nearly stole all of Equestria's magic and took over the school, they decide to take it upon themselves to insure the evil filly stays out of trouble. By taking her into their home, and raising her like their own child.
All the while, Rainbow sets out to prove she can be a good mother, Applejack sets out to show Cozy the value of caring for others, and Twilight sets out to mend a strained relationship.
As for Cozy, well, she just wants everypony to know who's top dog.