A homeless man, sleeping rough under a bridge in a soiled military bedroll, becomes the center of a grim image of slow destruction. The title suggests he is a veteran, though the poem never says so outright. As he twitches in his sleep, the speaker compares him to a caterpillar being eaten from the inside by wasp larvae, which save the nerve centers for last.
The poem then turns to a bitter idea: the warm feeling we mistake for love may only be corrosion, a kind of bad digestion. Change happens, the poem says, but it isn't the hopeful kind. There is no chrysalis, no rebirth.
The speaker sounds quiet, clinical and deeply sad, describing the scene without pity or comfort. The mood is bleak and uneasy. In the final lines, the light over the river spreads like a chemical spill and blots out the stars, so even the dawn feels poisoned rather than hopeful.