Foxes were hunted by the ponies nearly to extinction. Now, they stay hidden, and ponies will never hear anything about them for their entire lives... Until the day one gets caught in Canterlot. From there, things can only spiral out of control and reach epic proportions.
Especially since another fox comes out of the shadows to claim his rightful place in life, awakening an ancient evil at the same time.
Really, the day couldn't be any better.