"Bob, Son of Battle" is a mild, unpretentious children's book about sheepdogs and Scots and such. A few years ago an English company screened the story, called it "To the Victor," and ended up with a picture that won all kinds of critical accolades. Now 20th Century-Fox has got its hands on the same little book, and again come up with a new title--it seems the first one (the name of a dog) had all the evil earmarks for a War Picture, a current boxoffice bane. But what goes with the title this time is not so remarkable.

Edmund Gwenn, veteran character actor that he is, gets the freest of reins in this innocuous little film--and he overacts his way magnificently through the role of an irascible old Scottish sheepherder, soaked in Scotch and fighting a losing battle with a heather-clogged accent. Plot concerns a couple of rival dogs, the annual sheepherding trials, and dastardly murders (of sheep) by one of the aforementioned canines.

Everything works out nicely--both dogs win the big contest (in alternate years, of course); both are suspected of sheep slaughter and almost got their heads blown off by an aroused peasantry. Peggy Ann Garner and Lon McAllister are tossed in as a casual and extraneous pair of callow lovers, and take up some of non-doggy footage. But, unless you're one of that strange breed that dotes on animal pictures. "Thunder in the Valley" is hardly worth the trip downtown.