A Square Grid on the Ground

Wandering down the concrete sidewalk past the front gate, I noticed a dark, heavy iron grate set flat into the curb. Its bars formed an orderly row of hollow square slots. Without hands, I nudged a fallen dry twig with my chin, steering it toward the edge until it slipped and dropped with a tiny clatter into the dark opening below. Sssss... a soft, drawn-out hiss whispered from my chest as I leaned forward on my four stubby feet, peering down through the sturdy bars. The metal felt cool and solid beneath my toes, resembling a deep, protective dungeon floor built right into the street.