Rosalind Thorne has slowly but assuredly gained a reputation as "a useful woman" - by helping respectable women out of some less-than-respectable predicaments. Her latest endeavor is a tragedy waiting to happen. Desperate Margaretta Seymore is with child - and her husband is receiving poisoned pen letters that imply that her condition is the result of an affair with the notorious actor Fletcher Cavendish.

Rosalind Thorne may not have a grand fortune of her own, but she possesses virtues almost as prized by the haut ton: discretion, and a web of connections that enable her to discover just about anything about anyone. Known as a "most useful woman," Rosalind helps society ladies in need--for a modest fee, of course--and her client roster is steadily increasing.

December 1899. After the death of her beloved grandmother, Cleopatra Fox moves into the luxury hotel owned by her estranged uncle in the hopes of putting hardship and loneliness behind her. But the poisoning of a guest on Christmas eve throws her new life, and the hotel, into chaos. Cleo quickly realizes no one can be trusted, not Scotland Yard and especially not the hotel’s charming assistant manager.

Librarian Sylvia Ashe knows nothing about her past, having grown up without a father and a mother who refused to discuss him. When she stumbles upon a diary that suggests she's descended from magicians, she's skeptical. After all, magicians are special, and she's just an ordinary woman who loves books. She seeks answers from a member of the most prominent family of magicians, but she quickly learns that finding the truth won't be easy, especially when he turns out to be as artless as her, and more compelling and dangerous than books.

England, 1920. Eleanor Swift has spent the last few years travelling the world: taking tea in China, tasting alligators in Peru, escaping bandits in Persia and she has just arrived in England after a chaotic 45-day flight from South Africa. Chipstone is about the sleepiest town you could have the misfortune to meet. But then, from the edge of a quarry, through the driving rain, Eleanor is shocked to see a man shot and killed in the distance. Before she can climb down to the spot, the villain is gone and the body has vanished.