Recurrent invasions racked the city of Theodora in the centuries of its history; no sooner was one enemy routed than another gained strength and threatened the survival of the inhabitants. When the sky was cleared of condors, they had to face the propagation of serpents; the spiders' extermination allowed the flies to multiply into a black swarm; the victory over the termites left the city at the mercy of the woodworms. One by one the species incompatible to the city had to succumb and were extinguished. By dint of ripping away scales and carapaces, tearing off elytra and feathers, the people gave Theodora the exclusive image of human city that still distinguishes it.
But first, for many long years, it was uncertain whether or not the final victory would not go to the last species left to fight man's possession of the city: the rats. From each generation of rodents that the people managed to exterminate, the few survivors gave birth to a tougher progeny, invulnerable to traps and resistant to all poison. In the space of a few weeks, the sewers of Theodora were repopulated with hordes of spreading rats. At last, with an extreme massacre, the murderous, versatile ingenuity of mankind defeated the overweening life-force of the enemy.
The city, great cemetery of the animal kingdom, was closed, aseptic, over the final buried corpses with their last fleas and their last germs. Man had finally reestablished the order of the world which he had himself upset: no other living species existed to cast any doubts. To recall what had been fauna, Theodora's library would preserve on its shelves the volumes of Buffon and Linnaeus.
At least that is what Theodora's inhabitants believed, far from imagining that a forgotten fauna was stirring from its lethargy. Relegated for long eras to remote hiding places, ever since it had been deposed by the system of nonextinct species, the other fauna was coming back to the light from the library's basements where the incunabula were kept; it was leaping from the capitals and drainpipes, perching at the sleepers' bedside. Sphinxes, griffons, chimeras, dragons, hircocervi, harpies, hydras, unicorns, basilisks were resuming possession of their city.