Death of a Queen — Christopher St. John Sprigg

Give up your foolish plan. If not you dieWhen elderly Queen Hanna discovers the anonymous letter in her dress pocket, she knows someone in her household is spying on her. The queen is secretly planning a ceremony of atonement that she hopes will secure the royal succession. Amateur sleuth Charles Venables is invited by the queen's son Gustav to help identify the spy quickly and discreetly before her next public appearance. But on his first night in Iconia, Queen Hanna is strangled with a museum relic known as the 'Curse of the Herzgovins'. Venables knows an all too human hand is involved, but how was the murderer able to enter the queen's heavily guarded chamber? And why was the body found wearing the royal ceremonial robes rather than the clothes she had retired in?