A young RAF fighter pilot who has battled with his diminutive stature all his life, is shot down over France and ends up in Stalag Luft III. On a working party clearing an orphanage after a Lancaster bomber crashes. He discovers a cupboard full of nuns habits. He steals one and uses it to affect his escape. This is just the beginning of his bid for freedom. While his girlfriend fights a war of her own as a secret agent in occupied France.