Three British officers form a bond as they flee a POW camp at the beginning of World War II. Naive Jack Rose (Tom Hardy) and honourable Tom Willis (Laurence Fox) are recaptured and taken to the notorious Colditz Castle. The third, ruthless and self-assured Nick McGrade (Damian Lewis) escapes to London. McGrade quickly joins Lt. Col Fordham's M19, a secret government agency responsible for assisting camp escapees. When he seeks out Jack Rose's beautiful girlfriend Lizzie (Sophia Myles) to tell her of his capture, a fateful love story begins. Meanwhile, Rose and Willis try in vain to escape the unforgiving Colditz with the help of fellow POW, Canadian Airman Rhett (Jason Priestley). But when McGrade discovers that Rose has finally escaped, he faces a grave decision - to lose the love of his life or use his position to inform the Germans of his friend's whereabouts.