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.

It was a misty Wednesday morning. Inside the Gestapo headquarters, you could cut the tension with a knife. There was a traitor in their midst: Someone had leaked a list of the SS to the British press. The head of the Gestapo called me into his office. Panelled oak walls, a grand piano in the corner, rugs lining the floor—the place where he ordered executions every day.

July, 1940. Blitz-ridden London: Marnie Fern’s life is torn apart when her grandfather is killed in an air raid. But once she discovers that he’d been working undercover as a radio operative – or pianist – for the Dutch resistance, Marnie knows she must complete his mission – no matter the cost. Nazi-occupied Amsterdam: At the other end of the wireless, fellow pianist Corrie Bakker is caught in a dangerous game of cat-and-mouse as she desperately tries to keep her loved ones out of the line of fire – even if it means sacrificing herself.

Berlin, 1941: Margarete Rosenbaum is working as a housemaid for a senior Nazi officer when his house is bombed, leaving her the only survivor. But when she’s mistaken for his daughter in the aftermath of the blast, Margarete knows she can make a bid for freedom.... Issued with temporary papers - and with the freedom of not being seen as Jewish - a few hours are all she needs to escape to relative safety. That is, until her former employer’s son, SS officer Wilhelm Huber, tracks her down.

Bristol, 1939. School leaver Maisie Miles suspects her father, a small-time crook, has an ulterior motive for insisting she gets a job at the W. D. & H. O. Wills tobacco factory but keeps it to herself. She's befriended by effervescent Phyllis Mason and kind-hearted Bridget Milligan who take pity on her and take Maisie under their wing. But beneath their happy-go-lucky exteriors, they all harbour dreams and worries about what the future holds.