When Stefania Carmichael steps into the mysterious world of Bletchley Park, she immediately finds herself signing the Official Secrets Act. In whispers, she is told that she’s been recruited because of her talent for languages. Before the war ripped Europe apart, Stefania was living in Rome, charming everyone she met, and engaged to the man of her dreams, handsome and brave Matteo. And now everything has changed. With secrets swirling around the building, Stefania finds it hard to know who to trust, until she forms a close bond with two other new recruits.

Pearl Harbor, 1941: On the morning of December 7, Ginny is flying her little yellow plane above the sparkling seas when she spots an unknown aircraft closing in on her. She recognises the red symbol of the Japanese fighter planes almost too late. Somehow, she manages to land unscathed, but the choices she is forced to make in the terrible hours that follow have tragic consequences....

Berlin Zoo, 1943: Ten-year-old Adelaide and her newborn sister are orphaned after a devastating night of bombing. Heartbroken and frightened, Adelaide runs to her mother’s closest friend, Katharina Heinroth, and the kind zookeeper takes the two little girls under her protection. As the bombing intensifies, Adelaide tries to shut out the horrors of war by caring for her tiny sister and playing with the adorable baby monkeys. But when Katharina organizes a dangerous operation to enable children and animals to escape the battle-scarred city, something goes wrong.

She steps into the room and it’s like going back in time. Catapulting her right into the heart of the 1940s. The spindle of the record player frozen and ready to play. The flowery wallpaper faded but intact. A soldier’s uniform pressed and hung on a door, coal still in the fireplace.

September 1939. London is in blackout; war has been declared, but Dulcie Treadwell can think only of her heartbreak over American broadcaster, Glenn Reeves, who didn’t say goodbye before leaving for Berlin. Posted to Bletchley Park, Dulcie must concentrate on helping the war effort by cracking the German Enigma codes. The hours are long and the conditions tough, with little recognition from above. Until she breaks her first code. Dulcie finally settles into something she was born to do. But just as she’s proving her worth, a shocking betrayal leads to Dulcie’s brutal dismissal.