The Kishwaukee bends through the low ground near Marengo, and on a July evening the fireflies come up out of the grass along it like the field is remembering something. Sinclair Family Landscaping mows the yards in town while that light still holds, trimming close around posts and beds so nothing is left looking half-finished. River-bottom ground grows fast and grows uneven, which makes a level cut something you earn rather than something you get. The best part of the day is the last look back from the truck — one lawn, entirely square with itself. Then on to the next street before the light goes.