The Unknown Object

In the City of Glass, everything was shiny and clean and tidy. The towers were so tall they touched the clouds, the streets were as smooth as mirrors, and flying cars glided overhead in neat lines without making a single sound.

The city had a thousand cleaning robots. One of them was a small, round, white robot with one big blue eye on a screen in his face, a little arm with a brush on the end, and rubber wheels that turned quietly: whirrrr... His official name was Cleaning Unit Z-7, but the children in the plaza called him Zirro.

Every morning at exactly five o'clock, Zirro woke up and rolled out to the Old Fountain Plaza, where he cleaned the same place in the same way: he swept up the dust, polished the glass, picked up sweet wrappers, and then wrote in his memory: Task complete. Nothing new.