Rule Number Forty-Seven

The next morning, Zirro searched everywhere for soil. He checked the streets, the rooftops and the glass gardens full of plastic flowers that never wilted. But he couldn't find a single speck of soil.

Then he stopped in front of a huge screen in the middle of the plaza, which spoke in a cold, orderly voice. It was the Supervisor, the electronic brain that ran the whole city.

"Where... can I find... soil?" asked Zirro.

"Soil is forbidden," replied the Supervisor. "Rule Number Forty-Seven: no organic materials may enter the city, because they cause mess and dirt. The cleanliness of the city comes first."

Then it added sharply, "Why do you ask, Cleaning Unit Z-7? Have you found something against the rules?"

Zirro quickly shut the hatch in his chest. "No... thing..." he said, and a tiny drop of sweat appeared on his screen.