Acclaimed hillwalking writers Ian R Mitchell and George Rodway tell the fascinating story of Aberdeen-born Alexander Kellas, and his contribution to mountaineering from the 20th century to the present day. Now a largely neglected figure, Kellas is the pioneer of high altitude physiology, his climbing routes still in evidence today. Follow Kellas' journey, which takes him from the Scottish Cairngorms to the Himalaya, and discover how his struggles and explorations have impacted upon mountaineering today.