Morning Domino Rally

I spotted a wooden domino block lying on its side beneath the bookshelf and decided our morning needed a little motion! Fredrick was watching calmly from the rug, so I hurried over to set up a brand-new game for us. Gripping the smooth rectangular block with both hands, I set it upright on the polished floorboard, then lined up three more blocks in a neat, curving row. At the very front, I placed a shiny metal bottle cap on its rim. With a quick tap of my green fingertip, the cap rolled forward, knocking the first tile—*clack-clack-clack!*—sending a cheerful chain reaction tumbling all the way to Fredrick's paws!