From the introduction: “This world is older than any of you know. Contrary to popular mythology, it did not begin as a paradise. For untold eons, demons walked the Earth. They made it their home, their Hell.” “… The last demon to leave this reality fed off a human, mixed their blood. He was a human form possessed ... infected ... by the demon's soul. He bit another, and another ... and so they walk the Earth, feeding. Killing some, mixing their blood with others to make more of their kind.” “Into every generation, there is a chosen one. One girl in all the world. She alone will wield the strength and skill to stand against the vampires, the demons and the forces of darkness; To stop the spread of their evil and the swell of their numbers. She is the Slayer.”