Rain washes over a pattern of bright concentric circles, and the poem watches what happens. At first the colors are vivid: blue, red, gold, brown. Then the water hits, and they run. Blue turns to a dull puce, red goes anemic, gold fades to pale amber against black rocks. The "spoors of industry" in the opening suggest these rings are traces left by human work, though the poem never says exactly what they are.
The speaker stays mostly detached, describing rather than commenting. But the images darken as the poem goes on. A "small and silent" trickle becomes a "flux," then an "open wound," and the landscape turns to "metal quarry, pierced with points of stone." Judging by these words, the speaker sees damage and quiet violence in the scene.
The last line, "Prey, unseen hunter," leaves it unclear who is which. The mood is cold, hushed, and uneasy, as if something harmful is happening slowly and without anyone noticing.