Lucy Cooke and Colin Stafford-Johnson turn their attention to the country's mountains. Lucy discovers the brains behind the mountains as she searches for a seriously clever crow - the raven. Colin travels to the wild lands of Snowdonia to discover how this dramatic landscape was formed, and we go behind the scenes with Wild Alaska Live team as they search for the walrus. We also discover how the mountains of Scotland have become the playground of golden eagles and investigate whether the UK will ever again play host to wild lynx.