May, 1471. The Wars of the Roses are reaching their bitter and bloody climax. Edward of York has claimed the English throne, and his supporters are extracting a savage revenge on all who supported the Lancastrian cause. Surrounded by enemies wherever she turns, the position of Margaret Beaufort, Countess of Richmond and mother to Henry Tudor, the last remaining hope of the House of Lancaster, is precarious to say the least.

Determined to protect her son whatever it takes, Margaret must rely on her sharp-witted clerk Christopher Ulswicke to be her eyes and ears. When four bodies are discovered in a London tavern, their throats slit, and Margaret herself is suspected of being behind the crime, it's up to Ulswicke to prove his mistress's innocence and unmask the real killer.