August on the Dionis bluff: the light comes low across the Sound in the late afternoon and every blade of grass throws a shadow. Murtagh landscaping mows and maintains Nantucket lawns through the season, trimming close to the fences and running a firm edge where the lawn meets the shell drive. North-shore yards run wide and open, and a wide lawn shows every wobble, so the passes get laid out with care. Cut, trim, blow off the walks, gather what's left — the same short list, kept faithfully. Then the low sun does the rest.