"As long as there have been demons, there has been the Slayer. One girl in all the world, a Chosen one, born with the strength and skill to hunt vampires and other deadly creatures, to find them where they gather and to stop the spread of their evil and the swell of their numbers. When one Slayer dies, the next is called and trained by the Watcher. A Watcher serves by finding the next Slayer, leading her on her path. It is the destiny of the Watcher to guide the Slayer. In the words of librarian Rupert Giles, "This world is older than any of you know, and contrary to popular mythology, it did not begin as a paradise. For untold eons, Demons walked the earth; made it their home -- their Hell. In time they (the demons) lost their purchase on this reality, and the way was made for the mortal animals. For Man. What remains of the Old Ones are vestiges: certain magicks, certain creatures" And Vampires."