The Blackstone loses its height in a hurry through Millbury, tumbling past the old dam works with a rush you can hear from the bridge. A.C.G. Excavation takes on that same water in its winter form, when it arrives as snow and packs itself against every apron and turnaround in the valley. The truck rolls out while the streetlights still wear halos of falling white, and Riverlin Street shows black pavement behind it before most kitchens have a light on. Sand and salt follow on the grades, because a Millbury hill glazes over quietly and without warning. Plowing, opening walks, and hauling back the piles are the whole of the work here, done so the morning simply begins on time.