Edinburgh, 1889. The murder of a nurse at the lunatic asylum awakens Inspectors Ian Frey and 'Nine-Nails' McGray on New Year's Day. Before the attack, the murderer was overheard talking to fellow patient Amy McGray, sister of 'Nine-Nails'. But Amy has been mute for five years. So why did she break her silence? And why won't she talk to her brother even now? McGray will do anything for answers - even if it means dragging Frey with him across the country, trailing a devious madman through the worst blizzard in memory, heading for Pendle Hill: home of the Lancashire witches.