Rainbow Dash wakes up in a bed of flowers in a cave as a filly with amnesia. Lost and confused, she's taken in by a goat monster named Toriel. That's okay though, as long as she has DETERMINATION she can get through this.
Rarity and Rainbow Dash aren't exactly close. After all, they're very different ponies with very little in common. Or so Rainbow Dash thought. A trip to Canterlot reveals that Rarity isn't exactly the pony that Dash thinks she is.
Everything fell apart for Rainbow Dash after the Mare Do Well incident. Bent on vengeance and driven by her raw emotions, Rainbow Dash becomes a villain that Ponyville won't soon forget.