Guy of Gisburne, knight and agent to Prince John, is all that stands between England and anarchy, fighting a shadow battle to protect the kingdom from those who would destroy it. Returning to England after foiling a plot to destroy Jerusalem, Guy of Gisburne is arrested and hauled to the Tower of London, John, England's regret in the absence of its monstrous King, needs his knight once more. A killer has broken into the Prince's most secure castle in the north and left a message, drawn on the skin of one of his victims, 'the circle is closing', signed with a handprint in blood. Is the threat genuine?