When Zecora recounts the ancient Zebra Legend of the Black Unicorn, a terrifying tale about a powerful and evil pony who eats souls, nopony thinks twice about her cryptic warning that the monster was only banished and not destroyed. Nopony even believes that it could be true, including the skeptical Twilight Sparkle. But the Black Unicorn is very real. She was banished one thousand-five hundred years ago that night, and is more than ready to return and exact her revenge.

But there's a catch. The time away from the magic-rich world she called home has not been kind to the Black Unicorn and she needs a new body. One that is young and has a strong potential for magic. She needs a girl with a Heart of Gold, a girl who embodies the best of all the Elements of Harmony.

And she finds one. But there's a catch in her plan. The girl's Heart of Gold is so pure that the Black Unicorn has no hope of controlling her, not unless she can get her to stumble into the Dark.

(Warning: There is a little bit of gore and the possibility for feels)