After devastatingly losing her battle against Starlight Glimmer in the Season 5 Finale, Princess Twilight Sparkle is shunned from true reality and must learn to live in the ways of this alternate dimension. In that dimension, she finds a banged-up Nightmare Moon huddling in some bushes, bleeding badly. Twilight has a great idea, and so she takes in Nightmare Moon as both a "daughter" and a pupil, raising her to be the best she can, making sure she won't try taking over the world (even though she was Nightmare Moon). However, both ponies must face serious challenges. Will they make it? Will Twilight be killed somehow by Nightmare, or will Nightmare's reign last forever once she finally achieves it?