It's 1560, and rumour shrouds the death of the one woman who stands between Lord Robert Dudley and marriage to the young Queen Elizabeth. Did Dudley's wife, Amy, die from an accidental fall? Or was it murder? Even Dr John Dee is uncertain. Then a rash promise to the Queen sends him to his family's old home on the Welsh Border in pursuit of a crystal credited with supernatural properties.

With Dee goes Robert Dudley. They travel with the entourage of a judge sent to try a Welsh brigand with a legacy dating back to the Battle of Brynglas. After the battle, many bodies were, according to legend, obscenely mutilated. Now another dead man has been found, similarly slashed.…