This is the long-awaited new 'Sir Geoffrey Mappestone' mystery. When the highly unpopular Henry Mappestone is found killed by a mysterious 'Black Knife' in the stables at Goodrich Castle, his last-surviving brother, the former crusader knight Sir Geoffrey, unwillingly inherits the castle and the rest of the family's estates in the Welsh Marches. Geoffrey has hardly arrived before his sister attempts to push him into a marriage that will ultimately provide an heir and, therefore, long-term stability for their family in a tense and troubled region. But while visiting his friend Bishop Giffard at a nearby estate, attempts are made on Geoffrey's life, and several other guests are killed. Are these deaths related to Henry's murder, to his potential brides, or to the rumoured murder of the Duchess of Normandy by Giffard's family, which Geoffrey has been asked to investigate? As Geoffrey tries to make sense of a maze of intrigue, further killings begin to destabilize the area, and threaten to lead to a Welsh revolt against the west of England.