“Exactly, young Grasp. The roots of these new species delved deeper into the earth’s crust, burrowing beneath our ancestors’ dirty landfills, searching for clean sources of water and minerals. But the roots, almost with minds of their own, made another discovery. They finally pierced reserves of undiscovered gas. For the tree dwellers, it was a defining moment with infinite possibility. The trees themselves had no use for it, but for the human parasites who populated the canopy, it was the leverage needed to get off the ground: a free source of heat and power! The trees provided warmth, habitat, and clean water for all the creatures emerging to live high up in the canopy. In turn, we newly evolving Dendrans could defend the forest from outside interference. Give-and-take. Nature truly is remarkable, though we can safely leave the realm of talking trees to children’s tales.”

The old man smiled and scratched at a scab on his shiny head. “But the cleverest piece of the puzzle was yet to come. Somewhere in the trees’ biological makeup, the roots that tapped the gas also instituted a filtering process. The gas was cleaned up, so to speak, the waste siphoned out and released as a harmless odor by the leaves. Harmless to Dendrans and other tree dwellers, that is. And so, this relationship has worked well for generations and those from outside who seek to infiltrate our country now pay the ultimate price of … asphyxiation!”

A few of the boys made deliberate strangling noises as they clutched their own necks.

“Yes, yes. Very amusing, I’m sure. But perhaps you wouldn’t find my words so hilarious if our little nation was under attack, hmm?”

If only the lecturer knew the half of it, mused Petronio.

A bell sounded and everyone started packing up their books.

“Your essays by tomorrow, please,” the professor called over the hubbub. “Remember, you are supposed to debate the difference between the so-called religious creation myths of Diana and her dark consort, Corwenna, compared to the hard facts of evolutionary dendra-chronology.”

The pupils ignored their teacher, pouring out of the hall for break. One of the other students offered Petronio a cheroot. He had no objections to a bit of false friendship, especially if it involved a free smoke. He joined the small group of boys in their secretive puffing outside and drifted along with them when they headed to the corner of a public square. Tables were laid out along one side in preparation for the lunchtime trade. A waiter sweeping the floor free of pigeon droppings and twigs scowled at the students, making it plain that it was not their custom he was after.