From The strange world of felt presences by Ben Alderson-Day and David Smailes.
On 20 May 1916, Ernest Shackleton, Frank Worsley, and Tom Crean reached Stromness, a whaling station on the north coast of South Georgia. They had been walking for 36 hours, in life-threatening conditions, in an attempt to reach help for the rest of their party: three of their crew were stuck on the south side of the island, with the remainder stranded on Elephant Island. To reach the whaling station, the three men had to cross the island’s mountainous interior with just a rope and an axe, in a journey that few had attempted before or since. By reaching Stromness they managed to save all the men left from the ill-fated Imperial Transantarctic Expedition.
They did not talk about it at the time, but weeks later all three men reported an uncanny experience during their trek: a feeling that “often there were four, not three” men on their journey. The “fourth” that accompanied them had the silent presence of a real person, someone walking with them by their side, as far as the whaling station but no further. Shackleton was apparently deeply affected by the experience, but would say little about it in subsequent years, considering it something “which can never be spoken of”.
Encounters such as these are common in extreme survival situations: guardian angels, guides, or even Christ-like figures have often been reported. We know them now as “third man” experiences, following a line in TS Eliot’s poem, The Wasteland:
“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”
Eliot had heard of Shackleton’s encounter, but could not remember the precise details – meaning that the “fourth” man became the “third”.