A new pony arrives in the quaint Ponyville, her name, Stormie Night, a Pegasus. At first she seems sweet and a lover of thunder and lightning, hence her cutie mark of them. As she arrives, she soon becomes friends with Rainbow Dash and Pinkie but the more they talk, the more the two ponies realize there's more to her than what meets the eye.
Realizing they must help her fight her inner demons, they delve into her dark mind, desperate to help and then get out of this nightmare, but how can you fight what you cannot see?