Walking Through Shadows describes a winter walk in memory of the author's friend, Clive Dennier, a popular Inverness journalist, who died in Knoydart in March 2013 but whose body was found only some weeks later. The journey begins at Whiten Head on the north Sutherland coast and ends at Kinloch Hourn in Knoydart, the place where Clive was eventually found. Mike Cawthorne undertook the walk with his friend, Nick (also a friend of Clive's), from mid-January to late February 2015. Their walk traversed the wildest and most remote areas of Britain, often in atrocious winter conditions. The walkers were entirely reliant on food parcels buried beforehand.

As well as describing some the last wild places in Scotland in the heart of winter the narrative explores themes of grief, chance, mental illness and ecological damage. The author's companion is struggling throughout with the effects of severe mental illness but sees in the walk the hope of some relief from this suffering. The walkers are asking a question: whether the hills can heal at a human level and whether the hills can themselves be healed. In the shadow of the Anthropocene Mike Cawthorne evokes the darkness of winter, of two individuals seeking answers, alone in a freezing wilderness that is both beautiful and moribund. In the context of an extreme mountaineering adventure, he is grappling with issues of vital importance to us all.