Sunderland, 1943: With the future of Britain uncertain, the shipyard girls fight to keep their lives on an even keel. Head-welder Rosie is just about managing to keep her double life hidden from little sister Charlotte's prying eyes. But Charlotte senses something is up and, with a secret this big, the truth is bound to come out. After a whirlwind wedding, Polly must bid farewell to her sweetheart as he returns to the front line. And there is something odd about yard manager Helen's newest recruit Bel. But in resolving to uncover the truth, Helen might discover more than she bargained for... Only by rallying together will the shipyard girls triumph.