1928. After the death of a maid at a glamorous society party, fortune heir Bryan Guinness seizes life and proposes to 18-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. 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 1930, 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 . . .