As dusk fell on a misty evening in 1521, Martin Luther - hiding from his enemies at Wartburg Castle - found himself seemingly tormented by demons hurling walnuts at his bedroom window. In a fit of rage, the great reformer threw at the Devil the inkwell from which he was preparing his colossal translation of the Bible. A belief - like Luther's - in the supernatural, and in black magic, has been central to European cultural life for 3000 years. From the Salem witch trials to the macabre novels of Dennis Wheatley; from the sadistic persecution of eccentric village women to the seductive...