Youngsters David Coote and Nick Edmett discover a previously unknown cave, with an underground stream running through it, exiting through one of three holes. For a lark, they move a few stones and shift its course so it goes through the second hole. When they return to the outside world, they discover that the world has changed. The stream that had always run through West Poley now runs through East Poley. Their friend, Trevor Hill, was apprenticed to a cruel miller. Now, with no stream to power his mill, he has has no need for Trevor, who joyously gets a job on the farm. On the other hand, their other friend, Susan Ford, and her grandmother, are to be turned out from their pasturage to make way for a new mill! It's a nice movie from the Children's Film Foundation with the message "Be Careful What You Wish For." The kids are clean cut and the nature photography is lovely. I saw the 47-minute version, trimmed by a quarter for television broadcast; that may account for its straightforward simplicity, which might be to your taste -- or not.

I saw this as a child 60 years ago and was even then amazed by the great natural drama of man innocently experimenting with nature with no idea of the consequences. These are only children who don't know what they are doing, but at least they have the good sense to restore order in the last minute before war breaks out between the two villages about the water. Grown-up men are known to cause much worse havoc in nature out of sheer irresponsibility with no sense to avoid wars.It's a delightful film really putting the children in the centre of the action as protagonists with even some sense of responsibility, while the leading grown-ups are only foolish, mean and angry. Richard Addinsell's music adds the final touch to this small but undeniable masterpiece of a charming children's play mirroring the great problems of the world and environment in a microcosmos of irresistible thought-provoking complications of trifling with nature leading even on to thriller excitement.