Calamity befalls the royalty of Equestria and, in lieu of plans that took decades to create and moments to ruin, control of the cosmos is bequeathed to the only pony Celestia had time to empower.
On the advent of her coronation, Princess "Derpy" De Raptura continues to adjust to life as Equestria's newest ruler, but soon finds that the power she was granted requires a greater sacrifice than she could ever have thought possible.