Even though her husband Matthew de la Roche, who treasonously supports the ascent of Mary Stuart to the English throne, has asked her to join him in France, Ursula Blanchard, Lady of Queen Elizabeth's Presence Chamber, is unable to go to him until she's carried out another delicate mission for her queen. A cryptic message from a murdered spy indicates that something dastardly is underfoot at Lockhill, home of scholarly, ineffectual Leonard Mason and his wife Ann. Elizabeth's Secretary of State, Sir William Cecil, needs an agent in Lockhill who can pick locks and rifle papers while passing as a plausible member of the household. Ursula, who's already stayed with the Masons and has some credentials as a governess to their brood of children, is the perfect, though unwilling, candidate. Arriving in the Berkshire house, she finds it the picture of innocence, with Leonard Mason's humorously obsessive attempts to perfect one of Leonardo da Vinci's most famous inventions thwarted by the fact that he's not very good with his hands. But the presence of some wall tapestries Mason could never have afforded alerts her to a deep-laid plot to topple Elizabeth. The stylish intrigue that follows ends by revealing almost as many traitors as there are children dining at the Mason table. After an uncertain start, this sequel to To Shield the Queen (1997) turns alternately rousing and clever, balancing finally and firmly on Ursula's piercingly divided loyalties to her monarch and her man.