"From now on, every ghost who enters the world of the dead will have to come with a story, the story of his or her life, and tell it to the harpies. It doesn't have to be a big adventure; it can just be a description of a day playing with the children, like Lyra's, or whatever it might happen to be. In exchange for this true story, the harpies will lead that ghost outside to dissolve into the Universe and be one with everything else.