The novel is presented as the diary of Morgana, a 15-year-old Welsh science fiction and fantasy fan, in 1979 and 1980. She and her twin sister Morwenna, both frequently using the nicknames "Mor" or "Mori", grew up playing and occasionally working magic with beings they call faeries in the hills of Wales. Several months before the start of the novel, their mother, who is described as both insane and a witch, attempts to gain more power to take over the world. The sisters are able to stop her, but in the process their mother causes them to be struck by a car, killing Morwenna and disabling one of Morgana's legs. Morgana begins mostly using Morwenna's name, though still typically going by Mori.
