Nightfall at the Sentinel Post

The dark crept over the grass, but the carnival doesn't shut down for sunset! Splattered in fresh mud, I marched from the puddle crater straight up to the towering black mailbox post by the sidewalk. Stuck right into the turf next to it was a reflective red bicycle safety reflector on a slender wire stalk. I grabbed the wire, leaned my entire weight back, and yanked it taut like a catapult trigger! Twang! The stem snapped back, vibrating furiously in the dim streetlight and flashing a sharp red beacon into the evening air. The perimeter is armed, and nobody slips past the night patrol uninvited!