A Wild Sheep Chase. (Whats going on?!)

Lately I been taken into this novel this way and that, going to the past of my character as well as in the glimpse of the future! Apparently theres this buddy named "The Rat" whose an awesome guy and all but had sent letters only to My Character, whose name I still have yet to find out. (In fact I doubt that you even learn his name at all!) As "My Character" remembers how he had come to this sheep picture with a Star shaped birth mark on him, he goes into detail about this old friend named "The Rat". obviously his name is meant to make you believe something is up with this guy, and judging how he refuses to talk to anyone but him is very suspicious indeed.