The Stormy Road to Canterlot

The Prequel to My Little Pony: The Movie: The Stormy Road to Canterlot by Sadie Chesterfield is the twenty-sixth book in a series of chapter books published by Little, Brown and Company and a prequel to the events of My Little Pony The Movie.

This book explores Tempest Shadow's backstory and reveals how she turned from a sweet and kind pony to the Storm King's trusted commander and one of the most feared ponies throughout the land.

Humble unicorn beginnings
The story begins with Tempest Shadow and Grubber spying on Canterlot from an airship hidden in the clouds. With the Friendship Festival soon taking place, they begin to plan out their attack, and Tempest decides to take a look around the city to find out where the castle entrance is and what each of the princesses look like. Disguised in cloaks, the two agents of the Storm King enter the city.

The story then flashes back to several years prior, when Tempest was a younger and bright-eyed unicorn. Growing up with her best friends Glitter Drops and Spring Rain, she dreamed of one day living in Canterlot and attending Princess Celestia's School for Gifted Unicorns. One day, while the three friends practice their magic with a ball, Glitter Drops and Spring Rain accidentally lose it in a dark cave. Tempest, the bravest of the three, ventures into the cave to retrieve the ball, but she inadvertently runs afoul of a vicious ursa minor. The ursa chases after Tempest and knocks her harshly against the cave wall, but she eventually escapes and regroups with her friends. Unfortunately, as a result of her encounter with the ursa minor, the top half of her horn had snapped off.

In the months that follow, Tempest waits for her horn to grow back, but it never does, and she hides her horn stump from others under hats. When Glitter Drops and Spring Rain finally convince her to see if her unicorn magic still works, she tries to levitate a ball, but her magic only comes out as uncontrollable energy that burns and disintegrates whatever it touches. Tempest apologizes for scaring and nearly hurting her friends, but they know it was just an accident. Despite her friends' patience and understanding, Tempest feels the relationship between them has irrevocably changed after losing her horn.

Several moons later, as Tempest passes the time doing non-magic-related activities, Glitter Drops and Spring Rain appear on her doorstep to inform her that they've been accepted into the School for Gifted Unicorns, having taken the entrance exams before the deadline passed. Tempest is distraught upon realizing her dream of attending the school will never come true, but her friends assure her that she'll get her horn back in time for the entrance exams next moon and they can all be together again. Regardless, Tempest concludes that without friends or magic, there's nothing left for her in Equestria, and she leaves her home after nightfall.