A quiet garden at sunset is interrupted when rain comes over the wall. The speaker doesn't treat it as ordinary weather. Rain becomes "that sudden creature," something alive that slips in uninvited, the way an animal might leap a fence. The final line, "with no reservation," carries two meanings. Rain arrives without booking a place, like a guest who never called ahead, and it also comes without hesitation or holding back. It simply pours in.
The speaker seems more amused and charmed than annoyed. There's no complaint about a ruined evening, only a light, playful wonder at how rain ignores boundaries. The wall suggests a border between inside and outside, private and wild, and the rain crosses it freely. The mood is calm but alert, with the hush of dusk broken by a small surprise. Because the poem is so short, it feels like a single caught moment: a breath, a shift in the air, and then the garden is wet.