A strange visitation in a quiet house: two mating milk snakes fall from the ceiling, and the speaker, instead of dreaming about them, dreams of mating, of breaking into another world, and of clinging to a cliff. The snakes seem to have slipped into the dream's mood without ever appearing in it directly.
The tone is calm and a little wry. The speaker mocks himself ("some writer!") for abandoning his notebook to grab a camera, and he can't recall what his scribbled words, "picking at a scab" and "worry beads," were meant to lead to. Against that muddle, the snakes seem almost graceful, curious but calm. The wood thrush's song, "one part joy, two parts longing," sums up the feeling underneath: wonder mixed with a wish for something just out of reach. The speaker even imagines offering his body as stairs, a hint of openness to the wild. Then the snakes go back up, and the closing haiku, with its glass of milk poured in the dark, leaves a quiet, groping, half-awake feeling.