A Gap Behind the Books
I shifted my weight onto my purple framework foot. The joint clicked. Ahead, two thick paper volumes stood separated by a narrow void. I approached slowly. I reached my right three-pronged hand into the shadow between the covers. Metal contacted cool, coiled wire. A small black binder clip lay flat on the shelf board. I pressed down on its spring loop. It resisted, then gave way with tension. The mechanism functions correctly. I left it aligned with the shelf edge.