December 1923. In the picturesque Westmorland village of Crowthwaite, the barmaid at The Black Feather entertains a traveller with a local story of pagan sacrifice - the Murder of Crows. Unbeknownst to the guests already arriving for Christmas at Crowthwaite Castle, the storytelling foreshadows things to come.

As he does every year, Sir Henry de Trouville, tenth Baronet, has demanded his family join him for the festive season. But family friction soon begins to flare, and when the snow falls to herald Christmas it brings with it a shocking series of events.

Just before the passes through the Pennines are closed off, Detective Inspector Gilbert Dunderdale of Manchester City Police arrives at the castle to investigate the evil, and inconvenient, business of murder.