The Case of the Two Pearl Necklaces (Musaicum Vintage Mysteries). Dorothy Fielding

Soon after receiving a beautiful pearl necklace set as a wedding gift from her husband, the bride is found murdered! Even the pearls are found to be fake. So, who killed the innocent bride? Where are the real pearls? Excerpt: "Kitty Walsh had just been watching the marionettes. At first with keen amusement; but suddenly they had become not funny at all—instead, a sort of ghastly parody on life. They looked so incredibly alive, their actions seemed too intelligent, and yet they were only puppets that were dancing, and making love, and even committing murders with such energy and dash. She shot a glance at Ronald Mills beside her it had been his idea that in lieu of another dance they should watch the Show for a while. He caught her eye and followed her back into the ballroom."