Peter Holstein writes his popular series of adventure novels under a pen name. With European politics boiling and his own neighbors suspicious of him, Peter debates whether it might be best to change his name for good. When Rosemary shows up at his door pretending to be a historian and offering to help him trace his family history, his question might be answered. But as the two work together and Rosemary sees his gracious reaction to his neighbors' scornful attacks, she wonders if her assignment is going down the wrong path.

Three years into the Great War, England's greatest asset is their intelligence network - field agents risking their lives to gather information, and codebreakers able to crack every German telegram. Margot De Wilde thrives in the environment of the secretive Room 40, where she spends her days deciphering intercepted messages. But when her world is turned upside down by an unexpected loss, for the first time in her life numbers aren't enough.

1906: Lady Elizabeth “Libby” Sinclair, with her love of microscopes and nature, isn’t favored in society. She flees to the beautiful Isles of Scilly for the summer and stumbles onto the dangerous secrets left behind by her holiday cottage’s former occupant, also named Elizabeth, who mysteriously vanished. Oliver Tremayne - gentleman and clergyman - is determined to discover what happened to his sister, with the help of the girl now living in what should have been Beth’s summer cottage...especially when he realizes it’s the curious young lady he met briefly two years ago.

When their father's death leaves them impoverished, Sarah Summers and her genteel sisters fear they will be forced to sell the house and separate to earn livelihoods as governesses or companions. Determined to stay together, Sarah convinces them to open their seaside home to guests to make ends meet and provide for their ailing mother. Instead of the elderly invalids they expect to receive, however, they find themselves hosting eligible gentlemen. Sarah is soon torn between a growing attraction to a mysterious Scottish widower and duty to her family.

Despite the fact that her daughter is not cooperating, Caroline, Duchess of Riverton, is determined to ensure every one of her children marries someone they love as much as she loved their late father. William, the widowered Earl of Blackstone, is delighted to have his days of escorting daughters approaching an end.