“Now — see those streams of ships? At night it’s easier to see their formations as they enter and leave orbit. You know, a surprising amount of the matйriel for this war comes from Earth itself. At the equator there are mines that tap the liquid iron of the planet’s core, for mass and energy. The home planet’s very lifeblood is poured into the throat of the war! Already, so it is said, the structure of the core has been so distorted by such mining that the planet’s natural magnetic field has been affected. But don’t worry. The Coalition lifts great stations into low orbit to protect us from any magnetic collapse…”

Pirius had learned that Nilis wanted him to speak openly. So he said boldly, “Commissary, I’m still not sure what you do all day.”

Nilis laughed. “Nor are my superiors.”

“But your achievements must be significant.”

“Why do you say that?”

“Because they earned you trophies. And this.”

“The apartment? Well, perhaps, though those jealous idiots on the Conurbation council always keep the best views for themselves!” He tapped his teeth. “You don’t know much about me, do you, Pirius? No reason you should. I suppose my enduring claim to fame is that I am the man who doubled the output of Earth’s farmland — and, of course, of every food production facility in the Galaxy.” He patted his generous belly. “It was long before you were born, of course. But every time you enjoy a hearty meal you should think of me, and offer up thanks.”

“How?…”

Ecology had long been deleted from the Earth. Outside of a few domed parks, the land was given over to nanotechnological machines, which, powered by sunlight, toiled to turn the raw materials of the air and the soil into the bland paste, nano-food, that was the staple diet of the whole of mankind.

“All I did was double the efficiency of those laboring little critters.” Nilis sighed. “The technology was simple enough. But still, it was a marvelous day for me when the speaker of the Coalition’s Grand Conclave herself brought a handful of nano-dust to a scraped-clean bit of ground — not far north of here, in fact — and released my food bots into the wild.”

Pirius didn’t know how to phrase his questions; he had never met a scientist before. “How did you figure out what to do?”

“By reading history, my boy. Who invented the nanobots that feed us, do you suppose?”

“I don’t know.”

“Come, come. What race?”

“I — human, of course.”

“Not so.” Nilis shook his head. “The Commission doesn’t lie — that would be very anti-Doctrinal. But it is happy to allow certain inconvenient truths to fade into forgetfulness. Pirius, it was the Qax, our occupiers, who first seeded Earth with nanobots. They did it to make us reliant on them, and later as a deliberate act of the Extirpation: by destroying our ecology they sought to cut our links to our past. And then, when the Qax fell and the Coalition took over, there were simply too many mouths to feed, too much ancient knowledge lost, to resist using the bots to feed the liberated swarms. Nobody knows that Qax machines are feeding them! But I knew, because I was curious, and I dug into various old libraries and found out. Then I checked to see if the Expansion had yet reached the Qax home World. Of course it had, long ago. So I applied for a study grant from my Office. I learned that the Assimilation officers had gathered a great deal of data on Qax nanomachinery, though their studies had been allowed to gather dust for centuries. With that, it was straightforward for me to revisit the basis of the food nanobots, and find ways to improve their operation. Straightforward — the work of ten years, but that is a mere detail.”

Pirius was impressed. “It was a great contribution to the war effort.”

Nilis looked at him quizzically. “Well, I suppose it was, though I didn’t intend it that way. My nano- food got me this apartment, and a source of funding — and, more importantly, a power base, of a sort; at least, a position of independence. Yes, I’m proud of my work, and I’m certainly not shy of shouting about it when it’s useful. But I certainly didn’t achieve it by thinking in the way we’re all supposed to, with that peculiar mixture of arrogance and narrowness that characterizes the Druz Doctrines. I was prepared to look into the murky corners of the past — I was prepared to accept the uncomfortable, paradoxical truth that though we have conquered a Galaxy we are utterly dependent on an alien technology!

“And, of course, the latitude I won as the Man Who Fed The Galaxy has allowed me to cultivate my garden. Come see. Don’t worry; I won’t ask you to get your hands dirty…”

Nilis’s “garden,” confined to the concrete troughs, was unprepossessing, just tangles and clumps and spindles of green, crimson, and black, some curled together. Everything was small, compact, tough- looking.

Nilis watched Pirius’s reaction. “So what do you think?”

Pirius shrugged. “All I’ve seen of nature is rats, and the algae you have to scrape out of air ducts, and nobody makes a pet of that.”

Nilis laughed. “Well, my little gatherings here are nobody’s pets either. I suppose you’d say they are weeds.” He picked up one scrawny growth, a green stem topped by a gaudy yellow flower. “This is a native plant, obviously. Its chlorophyll green has become mankind’s symbol, hasn’t it? Even though we try to stamp it out wherever we find it. Ironic! We understand its biochemistry, of course, but we’ve long forgotten the name our forefathers gave it. I found it growing in the heart of the city — of Lunn-dinn, right here. Our Earth is supposed to be managed, Ensign: paved over, milked as efficiently as possible by the nanobots. But even in the cities, where the concrete cracks, a little earth gathers. And where there is earth, plants grow, welcome or not. But look here.”

From a tangle of vegetation, Nilis pulled out leaves: one a neat oval shape but jet black, the other almost square, and brick red. Nilis said, “I found this black leaf on Earth — but it’s not a native! It’s actually from a planet of Tau Ceti. And this red leaf isn’t a native either; it comes from a system a thousand light-years away. I doubt if these little creatures were brought here on purpose; they traveled as spores in the recycling systems of starships, perhaps, or lodged in the sinuses of unwary travelers. Both come from worlds basically like Earth, though, worlds of Main Sequence suns and carbon-water chemistry, or else they couldn’t survive here.

“But even on worlds so similar to Earth, life can develop in radically different ways. All these leaves are photosynthetic; they all gather energy from sunlight. But only Earth life uses chlorophyll; the others use different combinations of chemicals — and so they aren’t green. Interesting; you would think that this black shade is actually the most efficient color for a gatherer of sunlight… On each world life is born, like and yet unlike any other life in the universe. Once it’s born it complexifies away, endlessly elaborating, until it has filled a world. And then we come along, with our starships and Expansions, and mix it up, complexifying it further.”

Pirius frowned. “If their biochemical basis is so different, they can’t eat each other.”

“Well, that’s true. But these plants coexist anyhow. At the very least, they compete for the same physical resources — the sunlight, say, or room in the soil; whoever grows fastest wins. There may be reasons to eat something even if not for the biochemistry; a concentration of some essential mineral fixed by your prey, perhaps. And look at this.”

He moved to another trough and showed Pirius a kind of trellis, no more than ten centimeters high, covered in tiny black leaves, with a green plant draped over it. “The miniature trellis is a tree- analogue from the Deneb system,” Nilis said, “and the green plant is a pea, from Earth. The pea has learned to use the frame as a support. And probably the trellis is using the pea for its own purposes, perhaps to attract other Denebian life-forms; I haven’t figured it out yet.” He smiled. “You see? Cooperation. The first step to an interstellar ecology, and all happening by accident. It wouldn’t surprise me to come back here in, oh, ten or fifty million years, and find composite life-forms with components from biochemical lineages once separated by light-years. After all, our own cells are the results of ancient mergers between beings almost as divergent, between oxygen-haters and oxygen- lovers.”