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.

February 1913. Lady Hardcastle and her diminutive but brave lady’s maid, Flo, have been invited by their friend JB McIntyre to spend the weekend at his recently renovated Tudor fort on a remote island off the Devonshire coast. But the holiday quickly turns sinister when first a number of valuable jewels go missing—and then a fellow guest is murdered with a most unusual weapon.

Edinburgh, 1911: When Maud McIntyre and her lady’s maid, Daisy, form a detective agency, they never dream their first case will take place at a glamorous house in the Scottish Highlands. But when the duchess of Duddingston, concerned that a notorious jewelry thief will target her lavish weekend party, employs Maud to go undercover as a guest to find the culprit, the agency has its first case to solve....

London, 1941: Miss Jane Treen is at her desk, strong black coffee in hand and fluffy ginger cat by her side, when her top-secret government work is interrupted by an urgent call to Devon. A woman has been found dead in a lake in a place where she shouldn’t have been. Jane needs to gather the clues and find the killer before someone else from the agency gets hurt… Shy and handsome code-breaker Arthur Cilento is bewildered by the arrival of the efficient Miss Treen and her cat Marmaduke.

In wartime England, Lane Winslow has been pulled out of her studies at Oxford and spends her days in London translating for the war office. Things are grim, and it looks like no one is going home for Christmas—that is, not until Lane's commanding officer orders her to drop everything to do just that. He’s loathe to send a woman, but a very important agent needs an escort into the country from an isolated cove in Scotland in just a few days, and Lane’s family connections in the north are the perfect cover for this mission of utmost secrecy.