Seeds of Passchendaele

Archie Falkner is trapped, wounded, in the mud of WW1 'no-man's land' at Passchendaele. German, Gunther Brunnen, finds him and drags him to safety in a shell crater and treats his wound. They smoke and discuss their families. Preparing to leave, Gunther is shot and killed by advancing British troops. Back home, a photograph of a woman and child is found in Archie's uniform pocket. Not remembering it, he places it where it may later jog his memory. Gunther's son Wilhelm is nursed in a WW2 prison hospital by Archie's daughter, Valerie. They fall in love and on visiting her home he recognises the photo as of his mother and sister. What is the connexion? Is it really his family? Are they related? Or was the photo looted from his father's body? He returns to Germany to find out.