Four in the morning, freezing drizzle, and the commercial lots along Laraway Road are wearing a coat of ice you cannot see until you are on it. That invisible hour is the one SubZero Snow & Ice Control, Inc. builds its year around. The trucks run the lots and drives while the village sleeps, blade first where there is snow to move, then salt broadcast across the entrances, the loading aprons, the striped walk to the front door. Out here on the Joliet edge of New Lenox the freeze and thaw trade places all winter long, and glaze can form on bare pavement between one pass and the next — so the answer is watching the sky and going back out. Come opening time, the first car turns in and nothing about the surface gives anyone a moment's pause.