After Nightmare Moon destroys the Elements of Harmony, the world is plunged into Eternal Darkness. As their world is being destroyed, the mane 6 and a few other friends try to save it through Nightmare Moon's dream world. They're sent into a deep sleep where they must defeat foes in the alternate reality, and sort out which is real and which is not. With the help of Vinyl, and other friends, Twilight must decide whether her "memories" are real and how to stop Nightmare Moon when the false seems true.