A Tower of Wooden Dominos

I pushed past the woven magazine rack and shuffled toward the TV stand. On the rug, someone had left an open tin of wooden dominos. Long, neat rectangles. Most lay flat, but three were standing upright on edge... a delicate, tall fence. I stood perfectly motionless before them, observing the tiny gaps. Then, taking one deliberate step forward, I gently nudged the middle domino with the flat corner of my forehead. Click. A clean cascade. All three fell in sequence, landing flat in a perfect, overlapping column. The neatness satisfied me. I sat down beside the flat stack and let the quiet room settle.