Bridgerton meets Agatha Christie and Downton Abbey in this beguiling new Regency set series, as drastic circumstances compel Lady Caroline Morton, the penniless daughter of a deceased earl, to join the "downstairs" working class as a lady's companion... whose duties soon involve solving a murder!

Following the suspicious death of her father, the Earl of Morton, and the discovery that she and her much younger sister have been left without income or home, Lady Caroline takes a post as a lady's companion to wealthy widow Mrs. Matilda (Matty) Frogerton.

Eager to introduce herself and her rather wild daughter to the ton, Mrs. Frogerton is pleased when they are invited by Caroline's aunt, Lady Eleanor Greenwood, to a house party in the countryside. For her part, Caroline is eager to see her little sister, who now lives with their aunt. But all is not well at the Greenwood estate . . .

For one thing, Lady Caroline's former fiance, Lord Francis Chatham, is a guest and refuses to speak to her. Worse, after a series of troubling harassments of the staff, an elderly family member is found fatally stabbed by a knitting needle. . . . As Caroline and an unexpected ally-Mrs. Frogerton-attempt to solve the chilling crime, they discover bizarre clues in the nursery as to who will be next. But they must make haste, for this heartless killer is engaged in anything but child's play . . .