It's the day before the first day of spring. Everypony is working hard with their jobs to help bring spring, except Comet. She's gone 2 years without lifting a hoof, and doesn't want to break her streak yet. Aqua wants to change that.
After a spell miscasts, the Mane 6, the Crusaders, the Princesses, and Derpy Hooves suddenly get stuck in the world of Warrior Cats. This story takes place after "The Last Hope."