Floating fluff is fairy dust, pollen on the subway. A green caterpillar climbs my sleeve, so I place it on the windowsill. It crawls up its surface. Light flashes onto us as we speed past a park. Then darkness. Caterpillar climbs but these windows don’t open. It forms a chrysalis on the edge. Glows in the dark for months. It emerges clear with green accents, flaps wings to grant wishes for underground travellers. One for rent money, two for loved ones, three for stillness, four for outrage. It lands on heaving shoulders, snoring noses, dusty work boots, flicks off fairy dust and launches again. It will dance for cleaners at three a.m., leap for wanderers on the tracks, sail for singers on their strums, night to night, stop to stop. Day to day trace the surface of the glass, flashing fire in the sunset. At sunrise it will burst into refractions—blue, green, white, gold—or fade lonely one dead night, floating from car to car.