The Shadow Man by J.R.R. Tolkien

There was a man who dwelt alone
beneath the moon in shadow.
He sat as long as lasting stone,
and yet he had no shadow.
The owls, they perches upon his head
beneath the moon of summer;
They wiped their beaks and thought him dead,
who sat there dumb all summer.

There came a lady clad in grey
beneath the moon a-shining.
One moment did she stand and stay
her hair with flowers entwining.
He woke, as had he sprung of stone,
beneath the moon in shadow,
And clasped her fast, both flesh and bone;
and they were clad in shadow.

And never more she walked in light,
or over moonlit mountain,
But dwelt within a hill, where night
is lit but with a fountain -
Save once a year when caverns yawn,
and hills are clad in shadow,
They dance together then till dawn
and cast a single shadow.