A death in diamonds

1957 - A young woman is found dead in a mews house a mile from Buckingham Palace, wearing only silk underwear and a a diamond tiara. An older man is discovered nearby, garrotted and pierced through the eye with a long, sharp implement. According to the police, a high society card game was going on downstairs that night. One of the players surely committed the murders, but each of them can give the others an alibi. When someone very close to her is implicated, the young Queen is drawn in to the investigation.