Strange as it sounds, the poem begins with a simple encounter: the speaker meets a man who communicates only in stones. Small pebbles fall from his "craggy lips," and they seem to promise something much bigger, boulders still to come. The speaker admits to doubting all this ("Despite my disbelief"), yet ends by predicting that they will soon be buried under "his mountain of rubble."
The speaker's feelings seem to shift from skepticism to uneasy resignation. They don't believe, but they also don't escape. The word "crushed" suggests dread, though the tone stays oddly calm, almost matter-of-fact, as if the speaker already knows what is coming.
The mood is eerie and quietly threatening. The title, "Igneous Prophet," hints that the man is a kind of seer, one whose warnings are as hard and heavy as rock. Judging by the imagery, the poem may be about how small warnings pile up until they can no longer be ignored, but it leaves that open for the reader to decide.