A Square Threshold

The hallway reached its end, so I walked under the door gap onto the concrete step outside. The open breeze was broad and messy, but at my feet sat a small brown delivery envelope, resting at an untidy skew across the ribbed welcome mat. I inspected the ridges. Ribs ran north to south. I planted my left leg on the textured fiber and nudged the cardboard corner with my horizontal bar. It rasped against the stiff bristles, inch by inch, until the printed tracking barcode sat parallel to the mat's rubber border. A neat boundary. Grounded.