Reservist Tommy Smart - who has made his fortune since the war selling army surplus - arrives at an army camp, with his chauffeur/valet, for two weeks' training. Bank manager Corporal Jones is in Tommy's squad. Sylvia, Jones' daughter, wishes to marry Lieutenant Robson, a National Service officer. Smart is under the orders of his old enemy Sergeant Thickpenny and R.S.M. Brittain; various parade ground antics ensue..