Jericho Coulter, the eldest of six fiercely devoted brothers, is entrusted with safeguarding his family and the secret that binds them together: the Sapphire mine. To keep tragedy from striking again, he allows no outsiders on their land. When two women stumble upon their ranch, claiming Jericho himself sent for one of them as a mail-order bride, he aims to send them straight back where they came from.

Left with an estate on the brink of bankruptcy after their father's death, Lady Marigold Fairfax and her brother open a private investigation firm marketed to the elite . . . to spy on the elite. Dubbed The Imposters, Ltd., their anonymous group soon becomes the go-to for the crème of society when they want answers delivered surreptitiously. But the many secrets Marigold learns about her peers pale in comparison to her shock when she and her brother are hired to investigate her best friend's father as a potential traitor.

Miss Amelia Fleming has a very good reason to hate the Earl of Langley. A year ago, her father drowned in the Thames after losing a fortune to Langley at cards. Now her family is broke, her fiance has broken their engagement, and the debt still hasn't been paid. Someone has to deal with the earl, but Amelia's brother doesn't have the nerve and her mother has fled to France. It's no business for a gently bred young lady, but the Earl of Langley is about to learn that Amelia Fleming is not your typical young lady . . .

Newly returned from finishing school, Lady Juliette Thorndike is ready to debut in London society. Due to her years away, she hasn't spent much time with her parents, and sees them only as the flighty, dilettante couple the other nobles love. But when they disappear, she discovers she never really knew them at all. They've been living double lives as government spies-and they're only the latest in a long history of espionage that is the family's legacy.

Cassandra Hale grew up knowing little about her parentage, and she had made peace with the fact that she never would. But her world shifts when a shocking deathbed confession reveals a two-year-old letter from Mr. Clark, the master of Briarton Park, with hints to her family’s identity. Stung by betrayal, Cassandra travels to the village of Anston only to learn Mr. Clark has since passed away.