The ancient aqueducts towering over the ancient city of Realb are decaying. In their crestfallen state, they cast stones into the streets that crush roofs and injure unsuspecting idlers. Some have sought damages from the public works departments. Others repented.
Yet the city engineers have carried our their inspections, and without false motives say that the structures are sound; that their demolition would be of great cost and little benefit to the city.
Early one morning, a young engineer, still scratching his head at the mystery that has befallen the city, ascends the aqueduct in search of an answer. Reaching a point high above the city, he is confronted by a wide-eyed kitten. Then another. More cats appear suddenly, as if his eyes were adjusting to the light. They lounge, idle, stare, and nap, their wary glances piercing through him. A stout, sprawling feline yawns, and a single rock tumbles from the aqueduct, followed soon after by a shriek and a skyward curse from the village below.
The engineer returns to the city, but does not reveal what he has found. Instead, he goes straight home. He gathers a pail of milk and fresh herring and carries them to the foot of a ledge from which the cats may descend to eat. He continues his routine day in and day out, and each day the cats nestle closer to where he had placed the food the day prior. Soon there are no rocks that fall from the aqueduct, but the villagers complain of the cats.
One day, the cats are corralled into a pen and taken away, save for a lucky who scurry onto the aqueduct to safety. A few days after, rocks begin falling onto the roofs. Again, the engineer is sent for to inspect the bridge. The next morning, rather than bring his tools, the engineer walks through the village with his pail of milk and a bucket herring.