Adelaide, 1931: Telephone switchboard operator Frances’ life is difficult as sole provider for her mother and adopted uncle. But it’s thrown into turmoil when she overhears a suspicious conversation on the phone, planning a murder. If a life is at risk, she should tell the police; but that would mean breaking her confidentiality clause and would cost her the job. And Frances soon begins to doubt the evidence of her own ears - it was a very bad line, after all. She decides to put it behind her and meets slightly dangerous nightclub owner Jack.

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.

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…

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.

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?

1915, London: Working in the dusty bookshop that her Aunt Violet mysteriously inherited, Hannah Merrill is accustomed to finding twists in every tale. But discovering her beloved best friend Lily-Anne – with a paperknife through her heart – in the middle of the bookshop, is not a plotline she saw coming. The case is anything but textbook. With the discovery of a coded German message, and Hannah’s instinct that Lily-Anne’s husband is keeping secrets, she determines to get to the bottom of it. She can’t do it alone though.

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.

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.

Britain is in shambles, as it recovers from the cataclysm of WWI. Although the war has ended, it takes effort to preserve the peace against hidden enemies striving to undermine or replace the government. There is a desperate need for recruits to fight this invisible war. Sophie Burgoyne can trace her lineage back to the ancient French kings and dukes of twelve centuries ago.A long pedigree doesn't help her when she only has a few pounds in the bank. Sophie knows she must take action, or she and her father, the vicar of Havering-under-Lyme, will face the horrors of genteel impoverishment.

Cressida Fawcett is heading to the English countryside for a weekend of cocktails and partying at her friend’s glamorous mansion, the location of a recent diamond heist. But just hours after her arrival, Cressida is woken by an almighty scream. Rushing to the landing, she looks down into the great hall to find a trembling maid standing next to the body of Harry, the friendly young chandelier cleaner. Everyone believes Harry’s death was an accident. But as Cressida examines the opulent hall and the beautiful grounds, she thinks something darker is afoot.

As England prepares to fight the Nazis, three very different women answer the call to mysterious country estate Bletchley Park, where the best minds in Britain train to break German military codes. Vivacious debutante Osla is the girl who has everything - beauty, wealth, and the dashing Prince Philip of Greece sending her roses - but she burns to prove herself as more than a society girl, and puts her fluent German to use as a translator of decoded enemy secrets.

London, 1922. Between gallivanting in his Rolls-Royce and darkening the doorways of London's hotspots, Lord Reginald "Rex" Bankes-Fernsby has almost succeeded in banishing the battlefield nightmares that plague his sleep. Pity he can't say the same about that nagging lack of direction in his life. If only he were like his best friend Freddie—self-assured, suave, and up to his ears in secrets. But when Freddie is murdered, Rex doubts the verdict. Was Freddie really cut down while up to no good, or was he killed in the line of duty?

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.

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.

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?