A nor'easter shows its hand over the harbor long before it reaches the streets — the sky flattens, the wind turns, and Boston starts listening. All Star Landscaping & Masonry Service takes snow removal in the tightest parts of the city, where a plow has to thread between parked cars, hydrants and a stoop that opens straight onto the sidewalk. Storms here rarely finish in one sitting; they come in shifts, and so does the work — clearing, salting, returning when the wind fills a driveway back in. The reward is the sound of a car pulling out at six in the morning without a single spin of the tires. Cleared pavement, dark and wet under a streetlight, is its own kind of finished.