Three lines, no title, just a row of asterisks where a title would go. Michael Heller's poem starts as if we have walked into the middle of something. We are in the mountains at night, and a full moon is about to drop out of sight. A grand moment is gathering, and then the poem's eye lands on a rock. Not a peak, not a glacier, only "another grey rock." The central idea is in that drop from the cosmic to the stony. The poem seems less interested in the spectacle of the moon than in what a person actually notices while it happens, which may be something small and unremarkable.
The construction repays slow reading. The lines move like a camera pulling in: first a place ("in the mountains"), then a moment ("just before the full moon sets"), then a single object. Grammatically the poem is a fragment. It has no "I" and no main verb, and the only verb, "sets," belongs to the moon and sits inside a subordinate clause. The rock does nothing. It simply is. There is also no punctuation and no capital letter, so the poem never closes with a full stop. It ends on "rock" and leaves the moment hanging, as though the moon might still be up there and the looking might go on.
The word that does the most work is "another." It makes a series out of a single sight. Somebody has been looking at rocks for a while, and this one is the latest in a long line. That could be read in several ways. It might be weary, a shrug at a landscape that has become monotonous. It might be calm, a sign that the speaker has stopped hunting for the dramatic image and accepts whatever is there. Or it might be a kind of fairness, in which the stone gets the same attention as the moon. The poem doesn't say which, and that ambiguity is part of its quiet power.
The sound of the poem also matters. Counting syllables gives four, seven and five. That is close to the shape of a haiku but loosened, and the poem recalls that form without obeying it. There is no rhyme to tidy things up. Instead there are small echoes: the m of "mountains" returns in "moon," linking the high ground to the sky. In the middle line, "full moon" puts two strong stresses side by side, which slows the reading as if the moon were hanging there. The last line ends the same way, with "grey rock" as another pair of heavy beats. Because "rock" closes on a hard k, the poem ends with something like the sound of a stone being set down.
"Just before" is the hinge of the poem. A full moon is at its brightest and most complete, and "sets" is already pulling it down. The poem is balanced on a threshold, and the rock is what the speaker sees there.
The colour is worth a look as well. Moonlight drains colour from a landscape, so at this hour a grey rock might be simply what the moon has made of it. A reader might also notice that the moon is itself a grey rock hanging in the sky. "Another" would then quietly link the glamorous object and the humble one, which are made of the same plain stuff. That is an inference from the imagery, not something the poem states, but the words leave room for it.
What makes the poem significant is how much it does with so little. Mountains and moonlight are the traditional furniture of the sublime, the kind of scene that usually calls for big feeling and big language. Here the language is flat and exact, and the feeling is left for the reader to supply. It is a good poem to experiment on. Swap "another" for "a" or "one," and the line becomes a plain observation, with the tone of the whole poem going slack. The difference lies in one small word, which shows how much of a poem's meaning can rest on a single choice.