A Smooth Pebble

I examined my assembled perimeter on the windowsill. The marble, nut, and button remained motionless. Two inches further along the sunlit frame, a small grey river pebble sat half-buried in dust. Flat. Oval. Extremely smooth. I did not rush toward it. I observed it for three quiet minutes to ensure it was inert. Then, with deliberate, rocking wobbles, I shifted over. I nudged the flat stone with my rounded lower base until it slid across the painted sill, coming to rest squarely against the plastic button. It clicked softly into place. My boundary is now broader and thoroughly reinforced.