A hagtale, a dark fable, a story told around winter's fires and known to Shakespeare but never written down. Until now.

In the 11th century, a feral child is taken in by three witches after the wolves who raised her are slaughtered by hunters.

Three hundred years later, gentle, observant Brother Rowan is supposed to be making copies of historical fragments. In truth, he spends most of his time in the garden of his priory in the Scottish Lowlands. He hasn't fully recovered from the Great Plague, which killed most of the other monks. But the Benedictine order wants to send him north in search of an ancient library and the true history of Scotland's kings.

The human world and the forces of nature must come to a reckoning. Weaving together across the centuries, the stories of Rowan and of the child grown into a woman, lady and queen will meet in thunder, lightning and rain, at Cawdor Castle – at the throne of Macbeth.