Murder in the Dark.

Summary: "One of the most exciting and dangerous of the adventures into which Phryne's fabulous and risky lifestyle has led her" ?Kirkus Reviews It's Christmas, and Phryne has an invitation to the Last Best party of 1928, a four-day extravaganza being hosted at the Werribee Manor House by the Golden Twins, Isabella and Gerald Templar. Phryne is of two minds about going. But when threats begin arriving in the mail, she promptly decides to accept the invitation. No one tells Phryne Fisher what to do. At the Manor House, she is accommodated in the Iris room. At the party she dallies with two polo-playing women, a Goat lady (and goat), a large number of glamourous young men, and an extremely rude child called Tarquin. The acolytes of the golden twins are smoking hashish and dreaming. The jazz is hot and the drinks are cold. Heaven. Until three people are kidnapped, one of them the abominable child. Phryne must puzzle through the cryptic clues of the scavenger hunt to retrieve the hostages and save the party from further disaster.