a manner, though she was previously a volcano goddess. Narrative causality The Disc's nature is fundamentally teleological; its basic composition is determined by what it is ultimately meant to be. This primary element, out of which all others spring, is known as narrativium, the elemental substance of Story. Nothing on the Disc can exist without a Story first existing to mould its destiny and determine its form. This is, perhaps, a take on the fact that nothing can ever happen on the Disc unless it is written in a story by Terry Pratchett. On the Disc, if a story or legend is told often enough and believed by enough people, it becomes true. This is known as the law of narrative causality. For example, characters in Guards! Guards! describe the marauding (noble) dragon as an "impossible" creature, yet it is able to fly and breathe fire because that is what dragons are expected to do. Similarly, a witch gone bad may meet a bad end after building a house of gingerbread. If a miller has a third son, he will invariably leave him only his cat. A hero will always win when outnumbered, since million-to-one chances are dramatic enough to "crop up nine times out of ten", but always lose when faced with "a little bald wrinkly smiling man" who is almost always highly trained in martial arts. Discworld witches often employ narrative in their magic, but consider it ethically tricky since it interferes with free will. Discworld wizards avoid doing so because narrative that severely strains credibility requires outright sources of magic to feed on, sometimes indiscriminately. Knowledge of stories, their use and how to change them forms the basis of many forms of magical power in Discworld physics. Pratchett characters who use and/or change stories include Lilith, Black Aliss, and Granny Weatherwax. The habit of many Discworlders to take metaphor literally has combined with the power of belief to produce some very odd areas on the Discworld. The Place Where The Sun Does Not Shine, for instance, is a deep crevasse in Lancre, incidentally located between A Rock and A Hard Place. Octarine The colour of magic on the Discworld, also referred to as the eighth colour. This fictional colour is strongly indicative of magic and can only be seen by wizards (who sometimes describe it as resembling a fluorescent greenish-yellow purple) and cats, who both possess "octagon