1568. The Virgin Queen Elizabeth I has ruled England for ten years, but refuses to name a successor, despite the rival claims that threaten her kingdom.
Bess of Hardwick, the new Countess of Shrewsbury, has secured her future with her fourth marriage to George Talbot. Ambitious and shrewd, Bess anticipates royal favour when she and the Earl are asked to give sanctuary to the fugitive Mary Queen of Scots.
But the Scottish queen rails against house arrest in a desolate castle and plots to regain her throne. The castle becomes the epicentre of intrigue against Elizabeth, the Earl blinded by admiration for the other queen. Even Bess’s own loyalty is thrown into question. If Elizabeth's spymaster William Cecil links the Talbots to the growing conspiracy to free Mary, they will all face the Tower