Just before six on a snow morning, North Quincy is a row of porch lights and unbroken sidewalks with the Neponset lying flat and grey at the end of the street. HiCleaners is out in that hour clearing what people actually walk on — front steps, paths, landings, drives and lots — down to the surface, not just skimmed. Wet coastal snow packs hard under the first few footprints, so the trick is arriving before the block wakes up. There is a specific satisfaction in a set of granite steps swept bare while it is still dark and the commuters are only starting to move. Winter in Quincy is mostly a question of whether the way out is open, and that answer is this company's work.