Clare, Dougal, Leo and Mike discover the secrets of ice. On a bobsleigh track in the Swiss Alps, Leo learns about the slippery properties of this frozen substance, whilst Mike gets first-hand experience of the devastating power of ice storms as he travels to the eastern United States. Clare and Dougal are sent on their own mission, as they find out how the mighty rivers of ice we know as glaciers are formed - how they shape our planet, and how to escape if you're unlucky enough to slip into one. Show less