Medical student Helmut Wegener lies mortally wounded in a Russian field hospital. He has recently had himself married 'by proxy' although he has never seen his bride. Now Imgard Wegener is to become a widow, so the dying man extracts a momentous promise from his friend, Peter Hasslick, a locksmith, to take over his identity. The wasover, Hasslick,now 'physician' Wegener returns home to Irma. Although his 'marriage' to Irma is happy and they have children, the fear of exposure never leaves him and the opportunities for blackmail are many.