Born with a perfect memory, Lady Elizabeth Beckett has become one of the world's most notorious spies, despite being the daughter of a duke. She is shielded only by her code name: Shadow. When young ladies of High Society begin disappearing from London, Eliza has no doubt who is orchestrating these crimes; a heinous man she has been investigating for years. Vowing to save them before they are sold to the highest bidder, she must risk everything to stop him.

Rose Portman, determined spinster, has a bit of a predicament. Her great aunt has challenged her to get married before Twelfth Night and promised that, if she does, Rose will inherit the perfect country cottage with the funds to maintain it. Rose has always wanted to get away from London and Society, and this could be her chance! But the catch is that Rose has to attend a holiday house party in York and find a husband among the guests. Worst of all… she must marry for love.

Kate Matcham needs a fortune or a husband. She wants neither. With a tainted inheritance in the balance, she receives one offer to become a scoundrel's mistress and another offer of a marriage of convenience. Before resigning herself to a choice, she accepts the invitation to visit a childhood friend, considering it a last hurrah before embarking on a bleak future. The visit goes sideways when she falls for the gentleman her friend intends to marry, a man well out of Kate's league—and one who seems to be hiding something.

Lady Ludmilla Windmere is mortified. The spinster extraordinaire has fallen in love with her best friend, and that cannot be. The problem? She hasn't met him. Not once. For they have only ever corresponded by letter. When she sets out to uncover his identity, her world shatters. For Addy turns out to be none other but London's worst rake. Adrian St. Addington is perturbed. The rakehell extraordinaire is developing a marked tendre for a spinster, and that cannot be. The problem? She might be mistaking him for someone he is not. Or, what is worse, know precisely who he is.

Grace Sinclair has been callously cast out of her home. And though taken in as an orphaned child by the vicar and his wife, her unsurpassed beauty makes it impossible for her to remain in the vicar’s household - with two daughters of their own about to enter Society, the vicar and his wife see Grace as nothing but competition. Thankfully, Grace’s estranged Aunt Bell has agreed to take her in to her home in London. But Grace soon learns her situation has just gotten much worse.

Madalene Dowding was devastated when her mother died, leaving her all alone. To honor her mother's legacy, she decides to use part of her fortune to open an orphanage. When a teacher at the orphanage goes missing, Madalene takes it upon herself to start looking for her, even if it means taking her deep into the unsavory parts of London.

Julia Cummings has long been acquainted with loss - her mother, her brother, her sister, her friend, all gone too soon. But the loss that pushed her grief to the limit as a young girl was that of her best friend, Lucas Jonquil, who abandoned her without looking back. Now, eight years later, Lucas has returned to Lampton Park, and Julia has steeled herself - she will never forgive the man who broke her heart.

Miss Dinah Ashmore has a problem: her sister has gone missing, and the constable isn’t taking it seriously. She decides to take matters into her own hands by hiring a Bow Street Runner, not understanding the danger she has put herself in. Nathaniel Calvert, Earl of Hawthorne, is an agent of the Crown. His assignment is to root out a radical group and bring them to justice. When Miss Ashmore mistakes him as a Bow Street Runner and explains her plight, he suspects that the missing sister might be connected to his case.

Eliza Rose is the perfect lady—accomplished in pianoforte, riding, and multiple languages—until a scandal disrupts her privileged world. The fallen Rose family has struggled to regain their standing until a fortuitous connection helps Eliza re-secure her family’s place in Society, giving her everything she believed she wanted.

Lady Sophronia Bremerton is a far cry from the typical debutante, but she’s the toast of London’s upper class for one simple reason: she’s a society columnist for the London Illustrated News, and the gentry loves seeing their exploits printed in the gossip pages. But Sophie has bigger plans - she aspires to be an investigative reporter. When a stuffy ballroom during yet another Season proves to be nothing more than the usual rumor mill, Sophie seeks respite in the library, alongside four other young women who, for their own reasons, are also looking for escape.

Elena MacKinnon has spent the last seven years training to become a proper English lady. When her childhood friend, Captain Theo Donovan, returns from serving in the Navy, he brings along with him Elena’s humiliation for the ill-advised and ardent love letter she wrote him before his departure, which he ignored entirely. Elena hopes to simultaneously stifle his memory of the letter and make him regret overlooking her, showing him just how fine an English lady she can be. The only problem? She is not English but a proud Scot—and her heart may be more enamored with Theo than ever.

When their elderly guardian dies, Faith Whitford is determined to set up house in Bath and look for respectable country gentlemen for her four sisters. She has no ambitions for mingling with the ton. What she did not expect was a new guardian, in the form of a London Beau to be appointed over them, nor that he would take any interest in their care.

Emma Caldwell doesn’t hate anyone—except for Hugh Warrilow, the man who jilted her older sister and left like a coward to join the army. Men are clearly not to be trusted, and Emma is determined not to give her heart to one. No, a marriage of convenience is the very thing to suit her.

When faced with an unwanted marriage, Alice Rosemeyer accepts an invitation to the estate of Larkhall. Determined to earn her future security without a husband, she begins operating as the anonymous Ace of Hearts, writing letters and offering advice on behalf of the men eager to secure a match at the close of the London season. If she can manage to keep her identity secret, her reputation intact, and avoid the arrogant house guest, Mr. Thomas Herring, she might just call herself successful.

Despite living at her father’s inn her entire life, Elizabeth Doyle has always managed to avoid involvement with the smugglers who frequently gather there. Until now. When a handsome smuggler is brought to her with dire injuries, Elizabeth risks everything to hide him - completely unaware that the wounded man is not who he appears to be. When an opportunity arises to infiltrate the notorious smuggling gang he believes caused his father’s death, Jonas Ainsworth, the Viscount Langton, pretends to be one of them.