A Czech concentration camp escapee takes the identity of a dead British officer to avoid execution. In a German POW camp with other Englishmen, he is forced to keep up a correspondence with the officer's estranged wife. She notices a difference in her husband's letters but wants to believe that he has changed for the better. His fellow POWs begin to suspect him of being a German spy as he is a little too English but his conspicuous courage during an escape attempt vindicates the Czech. If he does eventually reach England, how will she react?