The Christmas trees in Knightsbridge sparkle with festive joy, and there’s nothing more fun than Christmas cocktail parties to ring in the new year of 1922. Camille Divine, known as Lady Camille Divine, has decorated her little house in Birdcage Mews with glistening decorations and a beautiful Christmas tree, but she has more on her mind than the festive season.

1929: Miss Clara Vale is a woman ahead of her time. Rather than attending Oxford to bag an eligible Duke (as her mother, Lady Vale, so desperately hoped), she threw herself into a degree in chemistry, with aspirations to become a scientist in her own right. But the world isn't ready for Clara. Unable to land a job in science because she's a woman, she is stuck behind the desk at a dingy London library. Until her estranged Uncle dies suddenly, leaving her his private detective agency, and laboratory, in his will.

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.

Lady Emily Hardcastle is an eccentric widow with a secret past. Florence Armstrong, her maid and confidante, is an expert in martial arts. The year is 1908 and they've just moved from London to the country, hoping for a quiet life. But it is not long before Lady Hardcastle is forced out of her self-imposed retirement. There's a dead body in the woods, and the police are on the wrong scent. Lady Hardcastle makes some enquiries of her own, and it seems she knows a surprising amount about crime investigation...

June 1933. Independent, young Kitty Underhay has been left in charge of her family’s hotel, The Dolphin, on the tranquil English coast. But when several rooms are broken into and searched, including Kitty’s own, she quickly realizes that something out of the ordinary is afoot at the hotel. Soon, rumors are flying in the cozy town that someone is on the hunt for a stolen ruby. A ruby that Kitty’s mother may well have possessed when she herself went missing during the Great War.

England. 1923. After a year away at finishing school where she learned etiquette, deportment, and the difference between a fish fork and a salad one, Kitty Worthington is eager to return home. But minutes after she and her brother Ned board the Golden Arrow, the unthinkable happens. A woman with a mysterious connection to her brother is poisoned, and the murderer can only be someone aboard the train. When Scotland Yard hones on Ned as the main suspect, Kitty sets out to investigate.

Fresh from teaching at her prestigious Swiss boarding school, Miss Atalanta Ashford suddenly finds herself the most eligible young lady in society when she inherits her grandfather’s substantial fortune. But with this fortune, and an elegant new Parisian home, comes a legacy passed down from grandfather to granddaughter…sleuthing discreetly for Europe’s elite. This young lady isn’t one to back down from a challenge and Miss Ashford must depend on her sharp wit and charm to solve her first case.

Istanbul, 1922. Lady Marigold Grey—former British spy and daring adventuress—sets out for England on a luxury train. But where Marigold goes, trouble follows. When the director of the train is murdered—and false evidence linking her to his death emerges—Marigold suddenly finds herself on the fast-track to becoming a prime suspect.

Olivia Denis is a content young wife with a carefree life in late 1930s London. Then her world is shattered with the violent death of her husband, Reggie. The police want to call it a suicide and close the case, but Olivia knows Reggie couldn't possibly have fired the fatal shot. Further mysteries surface surrounding her husband's death. Did the trustworthy Foreign Office employee betray government secrets? Was his murder linked to the death of a German embassy clerk the same night? And who searched their flat?

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....