The location and timeline in which the story takes place are both currently unknown.
Though Rule Book's previous mission to protect a ghoul client has proven to be a miserable failure, his attempts at seeing out the ghoul's final request may just improve the pegasus' luck. Upon discovering an advanced and curious robotic pony, Rule Book is determined to find out what connects his late ghoul client to his new companion, and find a way to use it for his own gain... if the wasteland lets him live long enough to do it.
Rule Book is a mercenary pegasus - one that is not very good at his job - who desperately wants to jump his career to the next level. He craves excitement and opportunities to play the hero, but often never gets an opportunity because he is not a very capable wastelander. He lacks experience and good sense, which under ordinary circumstances would have gotten him killed a long time ago, but has managed to eke out a living as a guard through sheer luck.
The currently-unnamed robotic pony is a relic presumably from the pre-apocalyptic period, and is of an unknown manufacture. It is slightly smaller than the pony male it resembles, and is made of aluminium and plastic. Though heavily damaged and made of materials that are ill-suited to hazardous environments, the robot seems to be immensely intelligent, capable of analyzing information quickly and learning from experiences.