A person is awake in the small hours, looking out at a landscape where a single dull light glows far away. That's the whole scene, and it's enough. The hour and the distant, weak light make everything feel remote and quiet, as if the speaker is the only one awake.
Then the poem turns inward. The speaker's fear of being nothing is described as "fine fur," an odd and striking image. Fur is soft and close to the body, something you might stroke, but it also bristles when an animal is alarmed. So the fear seems both familiar and alive, almost like a creature that has settled on the speaker's skin. It isn't a loud panic. It's a low, constant feeling.
The mood is hushed, lonely and honest. The dull light outside may echo the speaker's sense of being small and faint, though the poem never says so directly. It leaves that connection for us to feel.