James made one of the worst mistakes of his life. He let someone else buy him a drink without watching them to make sure he didn't get drugged.
After waking up some time later, James realizes that he is somehow now inside the ponyverse.
When Fluttershy goes to get help from Ponyville, James follows her. He then learns that he has been turned into some sort of dragon-thing. James decides to have some fun buy killing and burning every pony and house he can find.