Bobby Singer has been a hunter since Sam and Dean Winchester were in diapers, and he's hunted every monster, spirit and demon there is. He's become a surrogate father to Dean and Sam, and their most trusted ally. They count on his knowledge to get them out of jams, but now that knowledge is disappearing-something is stealing Bobby's memories.

My name is Bobby Singer. In twenty-four hours I'm gonna lose my memory. So here's everything you need to know. Monsters, demons, angels, vampires, the boogeyman under your bed: I've seen it, I've hunted it, I've killed it. I'm not the only hunter out here, but there aren't as many as there used to be. Not near as many as there need to be. I've learned everything I can about every damned critter that walks, crawls, or flies, and I'm not gonna let that all be for nothing. I'm not going down without a fight. I'm not letting everything I've learned disappear. So that's what you're holding in your hands--everything I know. Anything that'd be useful for Sam, Dean, and the hunters that come after me. It's a guide to hunting...it's a guide to me. My last will and testament. Ya idjits.