Frances Wynn, the American-born Countess of Harleigh, enjoys more freedom as a widow than she did as a wife. After an obligatory year spent mourning her philandering husband, Reggie, she puts aside her drab black gowns, leaving the countryside and her money-grubbing in-laws behind. With her young daughter in tow, Frances rents a home in Belgravia and prepares to welcome her sister, Lily, arriving from New York - for her first London season.

Isabelle Shelton has always found comfort in the predictable world of her mother’s dressmaking shop, Mrs. Shelton’s Fashions, while her sister Sylvia turned her back on the family years ago to marry a wealthy doctor whom Izzie detests. When their mother dies unexpectedly, the sisters are stunned to find they’ve jointly inherited the family business. Izzie is determined to buy Sylvia out, but when she’s conscripted into the WAAF, she’s forced to seek Sylvia’s help to keep the shop open.

Frances and George are enjoying some well-deserved leisure time in Paris when an old acquaintance from London, Alicia Stoke-Whitney, seeks Frances’s help to investigate a personal matter. Alicia’s daughter is being courted by Carlson Deaver, a wealthy American shadowed by a very suspicious tragedy. Less than a year ago, Carlson’s wife, a former actress, was murdered, her body discovered in one of the more dubious quartiers in Paris. Though authorities guess it was a robbery gone wrong, no one was ever brought to justice.

Liverpool, 1935: Raised in a strict Catholic family, Viv Byrne knows what’s expected of her: marry a Catholic man from her working-class neighborhood and have his children. However, when she finds herself pregnant after a fling with Joshua Levinson, a Jewish man with dreams of becoming a famous jazz musician, Viv knows that a swift wedding is the only answer. Her only solace is that marrying Joshua will mean escaping her strict mother’s scrutiny. But when Joshua makes a life-changing choice on their wedding day, Viv is forced once again into the arms of her disapproving family.

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.

London, 1861. Samantha Kingston has lived under the control of her overbearing uncle since the death of her parents six years ago. Trapped by the conventions of her gender and social class, she is desperate to find a way out. But when her aunt and uncle are murdered, the freedom she sought seems even further out of reach. A suspect in the crime, she finds herself on the run, unsure whom to trust, lost in the underworld she had only ever read about in the pages of a Dickens novel.

After more than a year of laying low, Billie, Helen, Mary Alice, and Natalie are called back into action. They have enjoyed their time off, but the lack of excitement is starting to chafe: a professional killer can only take so many watercolor classes and yoga sessions without itching to strangle someone...literally. When they receive a call from the head of the elite assassin organization known as the Museum, they are ready tackle the greatest challenge of their careers.

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.

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.

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.