A Test of Mass

The sill was behind me. I brought my weight down to the hardwood floor and advanced past the open bedroom door into the corridor. A fuzzy yellow sphere blocked the center of the hall. It possessed no engine, but it was unanchored. I stepped close and drove my clawed foot squarely into its flank. The sphere sprang across the boards, rebounding off the white baseboard with a dull hollow clatter before settling near the living room rug. I did not hurry. I marched after it, tail sweeping in a steady arc, and planted my talons firmly onto its crest. Compressed. Motionless. It yields to my authority.