New York, present day: On a whim, Juno Lambert buys a 1931 Underwood typewriter that once belonged to celebrated journalist Cordelia Capel. Within its case she discovers an unfinished novel, igniting a transatlantic journey to fill the gaps in the story of Cordelia and her sister and the secret that lies between them. Europe, 1936: Cordelia's socialite sister Irene marries a German industrialist who whisks her away to Berlin. Cordelia, feistier and more intellectual than Irene, gets a job at a newspaper in Paris, pursuing the journalism career she cherishes.

1940, Italy. Lili and Esti have been best friends since they first met at university. When Esti’s son Theo is born, they become as close as sisters. While a war seethes across borders, life somehow goes on—until Germany invades Italy, and the friends suddenly find themselves in occupied territory. Esti, older and fiercely self-assured, convinces Lili to join the resistance efforts. But when disaster strikes, a critically wounded Esti asks Lili to take a much bigger step: To go on the run with Theo. Protect him while Esti can’t.

Berlin, 1933. Aspiring actress Clara Vine arrives in Berlin to find work at the famous Ufa studios. Through a chance meeting, she is unwillingly drawn into a circle of Nazi wives, led by Magda Goebbels. British Intelligence officer Leo Quinn sees Clara as the perfect recruit to spy on her new elite friends. But then Magda reveals to Clara a dramatic secret and entrusts her with an extraordinary mission.

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.

Munich, 1935. The Bavarian capital is a magnet for young aristocratic Britons who come to learn German, swim in the lakes and drink beer in the cellars. What they don't see—or choose to ignore—is the brutal underbelly of the Nazi movement, which considers Munich its spiritual home. When a high-born English girl is murdered, Detective Sebastian Wolff is ordered to solve the crime. Wolff is already walking a tight line between doing his job and falling foul of the political party he abhors. Now Hitler is taking a personal interest in the case.