Emily and Jamie live near Hilltop Wood. Through Hilltop Wood runs Hilltop Stream, and the two children love to splash and play in its clear water. One day, they discover the stream has become dark and dirty, and the otter they used to see has gone. What can they do? This is the third enchanting story about Jamie and Emily's helpful Tomte friends, who help them make the stream sparkle again. But will the otter return?