The speaker describes a community convinced that the world is ending. Prophets read omens in the oddest places, and a huge flock of grackles darkens the sky and floods the lawns, so people bolt their doors. Yet the evidence doesn't add up. Coffee sits calmly in its cup, and traffic crawls along as usual. The big signs and the ordinary calm sit awkwardly side by side.
Then an old woman speaks, and the poem turns. The danger, she says, isn't the sky but "ourselves," and our habit of not paying attention to what is happening right now. The speaker doesn't comment on her words, which gives them quiet authority.
The mood begins with edgy, slightly comic dread, especially in the image of prophets consulting belly-button lint, then settles into something calmer and more reflective. The birds are strange and beautiful ("an iridescent sea"), and the closing phrase, "holy, unstable moment," suggests that every moment is both sacred and shaky, and worth noticing.