Thomas Hardy - The Shadow On The Stone

I went by the Druid stone
That broods in the garden white and lone,
And I stopped and looked at the shifting shadows
That at some moments fall thereon
From the tree hard by with a rhythmic swing,
And they shaped in my imagining
To the shade that a well-known head and shoulders
Threw there when she was gardening.

I thought her behind my back,
Yea, her I long had learned to lack,
And I said: ‘I am sure you are standing behind me,
Though how do you get into this old track?’
And there was no sound but the fall of a leaf
As a sad response; and to keep down grief
I would not turn my head to discover
That there was nothing in my belief.

Yet I wanted to look and see
That nobody stood at the back of me;
But I thought once more: ‘Nay, I’ll not unvision
A shape which, somehow, there may be.’
So I went on softly from the glade,
And left her behind me throwing her shade,
As she were indeed an apparition—
My head unturned lest my dream should fade.

Thomas Hardy

http://www.poemhunter.com/poem/the-shadow-on-the-stone/