The year is 1928, and after the death of a maid at a glamorous society party, fortune heir Bryan Guinness seizes life and proposes to eighteen-year-old Diana, most beautiful of the six Mitford sisters. The maid's death is ruled an accident, and the newlyweds put it behind them to begin a whirlwind life zipping between London's Mayfair, chic Paris and hedonistic Berlin. Accompanying Diana as her lady's maid is Louisa Cannon, as well as a coterie of friends, family and hangers on, from Nancy Mitford to Evelyn Waugh.

When a second victim is found in Paris in 1931, Louisa begins to see links with the death of the maid two years previously. Now she must convince the Mitford sisters that a murderer could be within their midst . . . all while shadows darken across Europe, and within the heart of Diana Mitford herself.