The Bad Sister (1978) is a tale of witches in contemporary life. Drawing from and reinterpreting James Hogg’s classic Gothic tale Confessions of a Justified Sinner, which focused on an evil alter ego, the novel is itself rather schizophrenic, alternating between a documentary account of the murder of Michael Dalzell and his daughter, tracked down by an editor, and a hallucinatory account maintained by Jane, the other, illegitimate daughter, who seems to have perpetrated the crime. Sometimes confusing but always intriguing fiction from Emma Tennant (http://en.wikipedia.org/wiki/Emma_Tennant)
Brought to the screen as a TV movie in 1983 by Laura Mulvey and Peter Wollen (http://www.imdb.com/title/tt0398728/)
395 pages in Canongate paperback edition
ISBN 978-1841950532
Emma Tennant