Geoffrey 'Geoff'/'Boy' Wellum joins the RAF at the age of 18 in May 1940, believing that the RAF needs every man available to fight the Luftwaffe. He quickly bonds with the other pilots in his squadron after a rigorous training regimen. On the ground, drinks, sports, and girls, in Geoff's case, Sarah, provide great comfort. However, the casualties exact a grueling psychological toll on him over time, and his tour of duty ends after 18 months.