The opening credits show huge crowds of workers going into factories. The narrator begins the film with nostalgic views of crowded beaches and remembering what it was like to eat an orange. Celia Crowson and her family go on holiday to the south coast of England in the summer of 1939 staying in the guest house which they come to every year. Soon afterwards the Second World War breaks out and Celia's father joins what was to become the Home Guard and her more confident sister Phyllis joins the Auxiliary Territorial Service. Fearing her father's disapproval if she moves away from home, Celia hesitates about joining up but eventually her call-up papers arrive. Hoping to join the WAAF or one of the other services, Celia instead gets posted to a factory making aircraft components, where she meets her co-workers, including her Welsh room-mate Gwen Price and the vain upper middle class Jennifer Knowles. Knowles dislikes the work they have to do at the factory, causing friction with their supervisor Charlie Forbes which eventually blossoms into a verbally combative romance. A nearby RAF bomber station sends some of its men to a staff dance at the factory, during which Celia meets and falls in love with an equally shy young Scottishflight sergeant Fred Blake. Their relationship encounters a crisis when Fred refuses to tell Celia when he is sent out on his first mission, but soon afterwards they meet and make up, with Fred asking Celia to marry him. After the wedding they spend their honeymoon at the same south coast resort as the Crowsons went to in 1939, finding it much changed with minefields and barbed wire defending against the expected German invasion. Just after returning to the factory, they find furnished rooms nearby to set up house together, but then Fred is killed in a bombing raid over Germany. Celia receives the news while working at the factory and at a mealtime shortly afterwards the band plays Waiting at the Church, without realising it had been played at Celia's wedding reception. About to break down, Celia is comforted by her fellow workers, as bombers from Fred's squadron overfly the factory en route to another raid.
The film was produced at Gainsborough Studios. Roger Burford had suggested to the producers that they create a film covering the entire British war effort on the homefront. The directors decided the task was too big and that the subject needed a fictional story to tie the material together. The directors originally wanted to call the film 'The Mobile Woman'. The dance hall scene involved real serving soldiers, airmen and firemen. Beethoven's Fifth Symphony is used liberally in the soundtrack.
