One of the most famous instances of the phenomenon took place during Ernest Shackleton's Antarctic expedition in 1916. The team's boat was trapped in ice and they were forced to make a grueling journey across mountain ranges and glaciers to a whaling station in Stromness Bay. Shackleton later wrote: "I know that during that long and racking march of thirty-six hours over the unnamed mountains and glaciers, it seemed to me often that we were four, not three." Later, the poet T.S. Eliot read Shackleton's account of a mysterious "fourth" man and took some poetic license with the idea, including it in his famous poem, The Waste Land. He turned Shackleton's fourth into a third — and this is where the phenomenon gets its name: 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 Gliding wrapt in a brown mantle, hooded I do not know whether a man or a woman But who is that on the other side of you?