Following the death of her husband, Lady Darby has taken refuge at her sister's estate, finding solace in her passion for painting. But when one of the house guests is murdered, her brother-in-law asks her to aid the insufferable Sebastian Gage - a fellow guest with some experience as an inquiry agent. While Gage is clearly more competent than she first assumed, Kiera isn't about to let her guard down, as accusations and rumors swirl.

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.

Miss Caroline has doubts when she receives an urgent invitation from a London law firm to discuss her late father's estate. After all, the dishonored Earl of Morton died without a pound sterling. But while helping Mrs. Frogerton's daughter navigate the high social season, Caroline meets with a cagey lawyer, Mr. Smith, who shares life-altering news—the earl composed a second will, leaving behind an undisclosed fortune. Mrs. Frogerton, however, is unimpressed with the firm's conduct and suspicious of their motives. Her instinct proves right when the two ladies find the office ransacked.

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.

For Emily, accepting the proposal of Philip, the viscount Ashton, was an easy way to escape her overbearing mother, who was set on a grand society match. So when Emily's dashing husband died on safari soon after their wedding, she felt little grief. After all, she barely knew him. Now, nearly two years later, she discovers that Philip was a far different man from the one she had married so cavalierly.

Tabitha, Lady Chesterton, the Countess of Pembroke, is newly widowed at only 22 years of age. With no son to inherit the title, it falls to a dashing, distant cousin of her husband's, Jeremy Chesterton, known as Wolf. It quickly becomes apparent that Wolf had consorted with some of London's most dangerous citizens before inheriting the title. Can he leave this world behind, or will shadowy figures from his past follow him into his new aristocratic life in Mayfair? And can Tabitha avoid being caught up in Wolf's dubious activities?

During the height of the Great War, Joanna Holmes and the Watsons receive a late-night, clandestine visit from Sir William Radcliffe, the Chancellor of the Exchequer, who brings with him an agonizing tale of blackmail; a case so sensitive that it can only be spoken of in the confines of 221B Baker Street. An unknown individual has come into possession of salacious photographs, which not only sullies the family name, but may force the chancellor to vacate his seat on the War Council where his advice is most needed.

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.

It’s 1924, and Blix Windway has made a career out of her wanderlust, giving lectures to ladies’ groups about everything from the flora of the American desert to the beauty of the Swiss Alps, but she needs new material for her talks. She strikes what seems to be an ideal agreement with an eccentric older lady. Blix will be her travel companion during a journey to Egypt, helping to smooth the way through customs and coordinate sightseeing tours.

It's 1911, and war is brewing across Europe. However, Melody Chesterton, an independent young woman with her own fortune, has more important things on her mind. Melody is determined to do more with her life than marry well; she wants exciting escapades with perhaps some romance sprinkled in along the way. Chaperoned by her older brother, Rat, who secretly works for Britain's newly formed Secret Service Bureau, Melody sets off for the first stop on her Grand Tour of Europe, Venice.