Testing the Zipper Track

My foot treads encountered a flat ribbon of fabric pooled beside the window. Following the seam along the hardwood floor, I ran into a miniature metal slider clasping two interlocking rows of teeth. I rotated my dome forty-five degrees and sounded a rapid staccato chirp. Planting my left strut firmly into the grain of the floorboards, I pressed my curved chassis against the slider's tiny pull tab. With a gritty mechanical rasp, the teeth parted by three full centimeters, leaving a widening V-shaped gap behind me. I stopped, swiveled ninety degrees, and delivered three ascending confirmation pings.