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.

Detective James Holton has been honorably discharged from the Army Criminal Investigation Division due to wounds sustained when an IED blew up near him. Now with the Lake City Police Department, he's rooming with his good buddy and partner, Cole, while he figures out his family dynamics. Physician Assistant Lainie Jackson is eighteen months out from an attempted murder perpetrated by her ex, which ended when she managed to grab the weapon and shoot him. When he appears to have survived and is back to finish the job he started, Lainie insists it's not possible.

Miss Gwendolyn Brinley accepted a temporary paid companion position for the Newport summer season, believing it would be a lark to spend the summer in America's most exclusive town. She suddenly finds her summer turning anything but amusing when her employer expects her to take over responsibilities as an assistant matchmaker. Tasked with the daunting prospect of attaining advantageous matches for her clients, Gwendolyn soon finds herself in the company of Mr. Walter Townsend, the catch of the Season, but a gentleman Gwendolyn finds beyond annoying.

Three years into the Great War, England's greatest asset is their intelligence network - field agents risking their lives to gather information, and codebreakers able to crack every German telegram. Margot De Wilde thrives in the environment of the secretive Room 40, where she spends her days deciphering intercepted messages. But when her world is turned upside down by an unexpected loss, for the first time in her life numbers aren't enough.

In 1942, Evie Farrow is used to life on Ocracoke Island, where every day is the same—until the German U-boats haunting their waters begin to wreak havoc. And when special agent Sterling Bertrand is washed ashore at Evie's inn, her life is turned upside down. While Sterling's injuries keep him inn-bound for weeks, making him even more anxious about the man he's tracking, he becomes increasingly intrigued by Evie, who seems to be hiding secrets of her own.