Mills (young Bill) enlists in the British Army to help his country against the Nazi threat. Not to be undone by his offspring, Graham (Old Bill) decides to do his part and sign up, too. There's a bit of trouble getting the upper echelons of the military to accept such an old recruit (who already served in WWI), but he's soon serving alongside his son in the war effort. No classic, but it's one of those feel good kind of movies that were so popular during WWII.