The poem is about how inspiration comes to him (in the form of a fox) into his mind and he ultimately inscribes it on the paper. Thus it is a journey from nothing in mind and a blank paper to inspiration and printed paper.
The poem consists of six stanzas having four lines each. There is no set rhyme scheme in the verse. The poet uses a number of literary devices like alliteration, personification, oxymoron, enjambment etc.
The poem begins with the words I imagine. Thus it is clear that it is all about the imaginations of the poet, not something real. The poet imagines he is in a forest in the midnight.
He is not alone there as something else is alive in addition to the time which is lonely and the blank page where his fingers move. In the beginning, it seems that he is imagining himself to be in the forest but by the end, we come to know that he is rather on his chair.
The forest here symbolises his mind in which something i.e. a thought comes, though he is alone having just running time and a paper as his companion.
Now, as there is something, the poet tries to see throw the window (perhaps refers to going into his mind). There is something but not as far as a star but very near (& hence cannot be a star) which is though deeper within darkness and is entering the loneliness i.e. killing the loneliness.
The stanza ends in suspense. However, by relating this stanza to the first one, we can say that it is the thought or an innovative idea which is about to strike his mind.
The something is now visible. It is a fox whose cold, delicately as the dark snow nose touches twig leaf. Dark snow is an oxymoron because snow is never dark and here means the cold nose of the fox.
The line indicates that the fox is coming near to him and right now only its nose is visible which is touching the leaves in the forest. Now two eyes also become visible. The phrase now and again now, and now, and now means that it is coming near but the line has not completed yet.
The first line is the final part of stanza 3′ last line (Enjambment). The fox is setting neat prints now and again now, and now, and now. Thus this repeated phrase shows the slow movement of the fox towards the poet.
Neat prints mean that they are quite visible in the white snow. In a deeper sense, they refer to the words which are being inscribed in the imaginary poem of the poet and which are quite visible.
The fox is setting footprints between trees very carefully. Its shadow seems to be lame as the snow near the stump (bottom part of a tree). The shadow is coming behind a body (of fox) which is about to come.
The phrase bold to come depicts that fox is cautious. This sentence also remains uncompleted which perhaps symbolises the pausing of the fox near the tree.
Across the clearing means the area without forest i.e. snow and in the deeper sense the paper. Suddenly, the fox reaches the poet. The poet feels an eye which is getting wider or bigger has deepening greenness, brilliance and is concentrated on its own business. The two eyes (in Stanza 4) have now merged into a single wider eye (in Stanza 5).
The fox with its stink (smell, which makes it feels us) suddenly enters the dark hole of the head i.e. the fox or the creative thought suddenly comes into his mind which was dark or without a clue or idea.
All this happened yet the window is starless still; the clock ticks i.e. everything is as normal (as in the beginning) but the poet’s creative idea is on the paper and hence a poem is written.