A Guiding Tether

The darkness beneath the propped floor vent was dense, carrying the scent of cold stone and forgotten brick. Entering blindly would be reckless. Kneeling at the threshold, I found an intact spool of blackened cobbler's thread resting against the skirting board. With measured turns of both hands, I unwound a generous length and looped its knotted end around an exposed iron screw near the duct frame. Letting the heavy brass escutcheon pin drop into the vertical shaft as a plumb lead, I watched the thread stretch taut into the abyss, marking a silent, disciplined descent.