Celestia has been observing the human race, and wants to study the rejects of their society.
Discord is bored with Celestias' jobs for him, and finds a kindred spirit in the lunatic prisoner.
Franky is Crazy. Sick. Twisted. Mad. Insane. Psychopathic. Moonstruck. Fucking crazy. Take your pick.
Authors note: The prologue is not required to understand the story. It also has gore, so faint of heart, beware.