Autumn 1941, and as female conscription looms, three women arrive at the Bell Works Factory in Hucknall to work on the Spitfire production line. Lily soon realises her real dream is to pilot the planes; Edna longs to be reunited with her evacuee daughter, but soon discovers she has a much bigger problem; and Jeannie fears the worst after weeks of no news from her fiancé. Despite all the heartache, with a bit of festive cheer and 'can do' attitude, The Engine Girls will pull together and do all they can to ensure Britain's safe for the New Year.

Pearl has given up on her dreams of being a journalist after being denied a promotion because of her gender. Joining the WAAF as a radio telephone operator for Bomber Command, Pearl's new job at RAF Fenthorpe serves two purposes – providing an income for her grandmother, and keeping a close eye on her younger sister, Thea, an instrument repairer at another Lincolnshire bomber station.

1942. Evie Sinclair has enlisted in the ATS to serve her country. Her mother disapproves, wanting her to stay and help run the household, but her father supports her bid for independence. Though conditions are austere and the training is intense, Evie is proud to become a qualified gunner girl, part of the team operating the anti-aircraft batteries. When she meets RAF bomber pilot Matt Goodwin at a dance, it's not long before they fall in love. But then tragedy strikes. Matt is killed on a mission, leaving Evie bereft - and expecting a child.

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.

England, 1940. Opening the box with trembling hands, she couldn’t believe it–a tiny baby lay inside. She gently lifted the newborn as it started to cry. Cradling the little one to her chest, she searched the darkness for any sign of whoever left it here. And as she rocked the child, something fluttered to the ground...a ration book.