Shoelace Gateway

I examined a dropped pair of black running shoes resting near the doorway. One red shoelace hung across the floorboards. Surface friction... high. Flexibility... total. I sat flat on my hinged knees to test the tension. I used both blocky hand clamps to draw the fabric cord straight. Near the mat sat an empty metal key ring and a clean wooden pencil stub. I wedged the pencil stub vertically into the shoe eyelet to act as an anchor pillar. Then I looped the red lace through the brass key ring, pulling it taut across the threshold like a miniature suspension cable. Zero sag detected. The entrance crossing is now marked.