Straight Through the Arc

Out in the neighborhood park plaza, my wheels tracked onto a broad field of smooth granite tiles. The indoor floors were behind me; fresh open space extended ahead. In the middle of the expanse, a curved sheet of fallen cardboard lay arched like a low bridge, pegged down at one edge by a stray pebble. A tunnel. I halted completely for two minutes, aligning my chassis with the tiny shadowed aperture beneath. Trajectory locked. *Vrrr!* Sudden motor surge. I blasted straight under the low curve, my roof clearing the corrugated underside by millimeters, and burst out the other side into the open sun. *Hummm.*