Newport, Rhode Island, August 1895: She may be a less well-heeled relation, but as second cousin to millionaire patriarch Cornelius Vanderbilt, 21-year-old Emma Cross is on the guest list for a grand ball at the Breakers, the Vanderbilts' summer home. She also has a job to do - report on the event for the society page of the Newport Observer.

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, 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.

At the end of her first unsuccessful season out in society, Lady Georgiana has all but given up on attracting a suitable man - until she receives an invitation to a masked Halloween ball at Broxley Manor. Georgie is uncertain why she was invited, until she learns that the royal family intends to marry her off to a foreign prince, one reputed to be mad.

England, 1925. After years shut away from the world, former detective Lord Edgington of Cranley Hall plans a grand ball to celebrate his seventy-fifth birthday. But when someone starts bumping off members of his scheming family, the old man enlists his teenage grandson to help find the killer, before one of them is next.

The Earl of Wrexford possesses a brilliant scientific mind, but boredom and pride lead him to reckless behavior. He does not suffer fools gladly. So when pompous, pious Reverend Josiah Holworthy publicly condemns him for debauchery, Wrexford unsheathes his rapier-sharp wit and strikes back. As their war of words escalates, London's most popular satirical cartoonist, A. J. Quill, skewers them both.

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...

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....

December 1927. Mystery-writer Marius Quin has one previous bestseller, endless looming mortgage payments, and no idea how to write his next book. When his childhood friend Lady Isabella Montague invites him to an intimate New Year’s Eve party hosted by a narcissistic actor, Marius seizes upon the distraction. With his perpetually glum Basset hound along for the ride, he navigates the snowy lanes to the opulent estate of Everham Hall. As the celebrations begin, fireworks light up the sky, champagne corks pop, and then the host is murdered…

Spring, 1918. The Great War is at a crucial stage, the Germans are making one last push into France, and the Allies are struggling to hold them back. Battle lines are shifting, and men, and their machines, are being sent up and down the front to shore up defenses. Major Heathcliff Lennox, and his batman Greggs, are told to report to their new HQ. They set off on a sunlit day to fly the distance, but the enemy is never far away, and disaster strikes. They're sent crashing to the ground behind enemy lines, where life, death, and love await.

Spring, 1905: Free-spirited like the Thoroughbreds she rides across the Kentucky countryside, Stella takes adventure by the reins when she's asked to attend a mysterious wedding in rural England. But once she arrives at the lush Morrington Hall estate, her cold and ambitious father confesses that he won't only give away his best racehorses as gifts - he has also arranged to give away his daughter as bride to the Earl of Atherly's financially strapped son. Stella refuses to be sold off like a prized pony. Yet despite a rough start, there's something intriguing about her groom-to-be.

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.

Londoner Madeleine Grant is studying at the Sorbonne in Paris when she marries charismatic French journalist Giles Martin. As they raise their son, Olivier, they hold on to a tenuous promise for the future. Until the thunder of war sets off alarms in France. Staying behind to join the resistance, Giles sends Madeleine and Olivier to the relative safety of England, where Madeleine secures a job teaching French at a secondary school. Yet nowhere is safe. After a devastating twist of fate resulting in the loss of her son, Madeleine accepts a request from the ministry to aid in the war effort.

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.

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.