There was a man who dwelt alone,
as day and night went past
he sat as still as carven stone,
and yet no shadow cast.
The white owls perched upon his head
beneath the winter moon;
they wiped their beaks and thought him dead
under the stars of June.
There came a lady clad in grey
in the twilight shining:
one moment she would stand and stay,
her hair with flowers entwining.
He woke, as had he sprung of stone,
and broke the spell that bound him;
he clasped her fast, both flesh and bone,
and wrapped her shadow round him.
There nevermore she walks her ways
by sun or moon or star;
she dwells below where neither days
nor any nights there are.
But once a year when caverns yawn
and hidden things awake,
they dance together then till dawn
and a single shadow make.
Tolkien had a thing about “shadow”, and this poem (here in its newer version from 1962) gives a good example. Shadow beings are wraiths, identified more by their shape than by their substance. They are both present and absent, or rather, they tend to be an absence that can become a presence. In this poem, a man without a shadow who appears to be dead (and hence absent) becomes a presence, to steal both girl and shadow. Now they both are elsewhere, in a realm on the edge of human experience.
Got to wonder which night it is when the caverns yawn. All Hallow’s Eve?