It's Christmas, and Phryne has an invitation to the Last Best party of 1928, a four-day extravaganza being held at Werribee Manor house and grounds by the Golden Twins, Isabella and Gerald Templar. She knew them in Paris, where they caused a sensation. Phryne is in two minds about going when she starts receiving threats. She promptly decides to accept the invitation - after all, no one tells Phryne what to do.
The nice men at P&O are worried. A succession of jewelry thefts from the first-class passengers is hardly the best advertisement for their cruises. Especially when it is likely that a passenger is the thief. Phryne Fisher, with her Lulu bob, green eyes, cupid's bow lips, and sense that the ends justify the means, is just the person to mingle seamlessly with the upper classes and take on a case of theft on the high seas - or at least on the S.S. Hinemoa, on a luxury cruise to New Zealand. She is carrying the Great Queen of Sapphires, the Maharani, as bait.
St. Kilda's streets hang with fairy lights. Tea dances, tango competitions, lifesaving demonstrations, lantern shows, and picnics on the beach are all part of the town’s first Flower Parade. And who should be Queen of the Flowers but the Honourable Phryne Fisher? It seems that the lovely Phryne has nothing to do but buy dresses, drink cocktails, and dine in lavish restaurants. Unfortunately, disappearances during this joyous festival aren’t limited to the magic shows.
Phryne Fisher, her sister Beth, and her faithful maid, Dot, decide that Luna Park is the place for an afternoon of fun and excitement with Phryne's two daughters, Ruth and Jane. But in the dusty dark Ghost Train, amidst the squeals of horror and delight, a mummified bullet-studded corpse falls to the ground in front of them.
Seven Australian soldiers, carousing in Paris in 1918, unknowingly witness a murder and their presence has devastating consequences. Ten years later, two are dead ... under very suspicious circumstances. Phryne's wharfie mates, Bert and Cec, appeal to her for help. They were part of this group of soldiers in 1918 and they fear for their lives and for those of the other three men. It's only as Phryne delves into the investigation that she, too, remembers being in Montparnasse on that very same day.