Doubting Thomas, by Andy Moxon

Who is the third that walks always beside you?
When I count, there is 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 brown mantle, hooded
I do not know whether a man or a woman
—But who is that one the other side of you?

T. S. Eliot

I find I’m always coming back to this quotation, this question.