"Witches, ghouls, possessed animals, even nebulous mountain-dwelling ogres, are neither discrete species of the otherwordly nor even are they firmly separable from humanity. They are, in a sense, all or any of us, which means, of course, that we are also, in a sense, them. These two states of being, human and troll, are separated only by magic and the passage of time, the former a somewhat obvious but the latter a no less essential element in the cultural myth of the troll."