A traveler sits facing backwards on a train, watching Welsh hills recede into a bluish distance. The speaker seems to be pregnant, judging by the "waxing moon" and the "wobbly" belly, and there's a quiet wistfulness in wondering whether they'll ever pass this way again. Then the focus shifts. The speaker realizes they've been looking straight through their own reflection in the glass, a pale, attentive girl facing forward, with hair like autumn fields. She seems to be a version of the speaker, or perhaps a glimpse of a younger self, looking toward what's ahead while the speaker looks back.
The mood is dreamy and reflective, with a light touch of humor at the end. The train stops, a platform "assembles itself," and the speaker wonders about a place whose name takes "two clearings of the throat," a nod to Welsh spelling and sounds. Distance and memory give way to something new and unfamiliar.