Breaching the Threshold Gap

I reached the base of the heavy front entrance door. Direct exit was blocked by a flexible rubber sweep strip running along the bottom timber edge. High friction barrier. Just beside the metal jamb, an unlatched mail drop slot let through a direct beam of midday sun. On the floor lay a flat metal bottle cap and a folded hardware receipt. I knelt down, smoothed the stiff paper strip, and wedged the curled end beneath the flexible rubber flap. Next, I leveraged the bottle cap into the gap as a rigid chock. The flap remained elevated by ten millimeters. A clear aperture now opens toward the outer world.