 During the middle years of the war, three men are called up to serve in the British Army.The Englishman Philip Hamilton (Underdown), the American David Morgan (Clanton) and the Irishman Smoke O'Connor (Michael Brennan) are conscripted into the Guards Division and report to their barracks at Caterham, Surrey.After going through strict training (including real Coldstream Guards Regimental Sergeant Major Brittain) they find themselves receiving emergency promotions.