Many settlements were made on rivers, but over time the waterway became less useful for transportation and drinking water, and prone to stink and to contribute to disease when used for human and industrial waste. So our forebears applied the “out of sight, out of mind” solution. The rivers didn’t disappear - they were just forced underground. We follow the “drainers” who illegally search out the rivers’ paths, seeing an eerily beautiful world beneath us. But can these waterways be restored to light and life? This lyrical film takes us around the world to find that the answer can be “yes”.