Downtown after midnight, an empty parking lot is lit like a stage, and snow crossing the beams makes the whole thing look busier than it is. Plow King Chicago works commercial ground on nights like that — lots, drives, loading docks and the aprons where trucks back in — pushing down to the surface and laying salt behind the blade. Storms off Lake Michigan can dump a heavy wet band on one side of the river and leave the other side merely dusted, so the route gets read fresh every time. The point is that at seven the doors open and the day happens as though nothing had fallen. Nobody sees the night's work, which is exactly the compliment.