The BBC's world-renowned 'Natural History Unit' has brought the marvels of the planet to millions of viewers using breathtaking photography and pioneering filming techniques. 'Natural World' is their award winning flagship series that presents surprising wildlife stories from across the world. Henry Williamson's enchanting novel 'Tarka the Otter' was a huge hit with children and adults alike.This delightful film sets out to find Tarka's descendents... 'Natural World' goes in search of otters on a short stretch of the River Torridge in Devon, immortalised 80 years ago in the famous novel. Do they still fish the same pools that Williamson described to millions of readers with such skill and relish? Otters were once considered to be vermin and were trapped and hunted for sport, but in the book they are portrayed as creatures that encapsulate freedom and the carefree enjoyment of the wild countryside. Today, our attitudes towards the otter and the natural world in general have changed. Do the lives of Tarka's great-great grandchildren reflect this shift? Combining well-loved fiction with modern-day fact, this film contrasts the dramatic events of the novel with actual events from a modern otter's life.