My name is Bobby Singer. In twenty-four hours, I will lose my memory. Here is everything you need to know. Monsters, demons, angels, vampires, the villain under your bed: I have seen them, I have hunted them, I have killed them. I am not the only hunter out here, but there are not as many as there used to be. Far from enough, actually. I have learned everything I can about every creature that walks, crawls, or flies, and I will not let it all be for nothing. I will not go down without a fight. I will not allow everything I have learned to disappear. So this is what you hold in your hands – everything I know. Everything that could be useful for Sam, Dean, and the hunters who come after me. It is a guide to hunting... it is a guide for me. My last will and testament.