set between (Luncheon with the Princess) and (Something Nobody Saw Coming) of 'Friends from Unexpected Places'
Trixie returns to Ponyville to make amends with Twilight, as well as her own brothers. while there, Trixie finds a new spell in Twi's library and tries it out, not knowing the consequences. as a result... everyone has turned into humans.
despite Lyra's fantasy being fulfilled, everyone is having trouble adapting to it, even with Requiem and her friends helping. hoping to find a way to reverse it, Twilight must venture into the one place said to have a reversal spell: deep in the Gryphon Kingdom, and who should help but a old 'friend' of Rainbow's.
the spell, unbeknownst to our heroes, has a side-effect and brings a old foe back from the dark abyss.
this isn't gonna end well, is it?