Who is the third who walks always beside you?
When I count, there are only you and I together
But when I look ahead up the white road
There is always another one walking beside you.

T.S. Eliot The Waste Land

The Third Man is the name attached to the unseen being experienced by people - often adventurers, mountaineers and explorers – in situations of extreme deprivation and near-death. Scientific researchers call it variously a 'sensed presence', a 'vivid physical awareness' or the 'illusory shadow person'.

One of the most famous Third Man encounters was experienced in 1916 by the explorer Ernest Shackleton, when together with some companions he sailed 800 miles in an open lifeboat to from the Antarctic to South Georgia, then fought his way across indescribably hostile terrain to reach a remote whaling station. The purpose of his supreme struggle was to get help for the members of his expedition stranded on Elephant Island, a desolate outcrop off the Antarctic Peninsula. He later wrote that during that last arduous journey he had an overwhelming sense of being accompanied by a powerful presence. Later he described it thus:

‘When I look back at those days I have no doubt that Providence guided us, not only across those snow-fields, but across the storm-white sea that separated Elephant Island from our landing place on South Georgia. I know that during that long and racking march of thirty-six hours over the unnamed mountains and glaciers of South Georgia it seem to me often that we were four, not three.’

John Geiger, governor of the Royal Canadian Geographical Society, fellow of the Royal Geographical Society and of the Explorers club, is a writer of non-fiction books who also experienced a sensed presence when threatened by a rattlesnake as a boy. In his recently published book The Third Man Factor, Geiger collates many of the extraordinary testimonies of people who escaped traumatic events with the help of a 'Third Man'. He also examines the scientific theories which try to explain it. Watch this John Geiger interview: