T.S. Elliot (1888 - 1965)

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?