June, 1554. Professional assassin Jack Blackjack has been despatched to the palace of Woodstock, where Queen Mary's halfsister, Princess Elizabeth, is being kept under close guard. Jack's employer has reason to believe that a spy has been installed within the princess's household, and Jack has been ordered to kill her. Jack has no choice but to agree. But he arrives at Woodstock to discover that a murder has already been committed. As he sets out to prove his innocence by uncovering the real killer, Jack finds the palace to be a place steeped in misery and deceit. But who among Woodstock's residents is hiding a deadly secret and will Jack survive long enough to find out?