Everything seemed normal in Ponyville when Celestia called Twilight and her friends to the castle for a very important mission. Some ponies were up to something. They didn't know what, but they knew it was bad. They set out to a remote area and try to find out what's happening.
I did not make this cover art.
Link to cover art: http://2.bp.blogspot.com/-p8iWZO6P2CM/TeWQWV86M2I/AAAAAAAAAJ8/AUb1UDVmlus/s1600/golem_metal.jpg