And yet still, with all the blossoming of human effort and confidence of the accelerando, there was a sense of tension in the air, of danger. For despite all the building, emigration, settlement, and inhabitation, there were still eighteen billion on Earth, and eighteen million on Mars; and the semipermeable membrane between the two planets was curved taut with the osmotic pressure of that demographic imbalance. Relations between the two were tense, and many feared that a prick of the taut membrane could tear everything asunder. In this pressured situation, history was little comfort; so far they had dealt with it well, but never before had humanity responded to a crisis of need with any long-term consistent sensible sanity; mass madness had erupted before; and they were the exact same animals that in previous centuries, faced with matters of subsistence and survival, had slaughtered each other indiscriminately. Presumably it could happen again. So people built, argued, grew furious; waited, uneasily, for signs that the oldest superelderly were dying; stared hard at every child they saw. A stressed renaissance, then, living fast, on the edge, a manic golden age: the Accelerando. And no one could say what would happen next.

Zo sat at the back of a roomfull of diplomats, looking out the window at Terminator as the oval city rolled majestically over the blasted wastelands of Mercury. The herni-ellipsoidal space under the city’s high clear dome would have been a pretty airspace to fly in, but the local authorities had banned it as too dangerous — one of many fascist regulations that bound life here — the state as nanny, what Nietzsche so aptly called the slave mentality, still alive and well here at the end of the twenty-second century, in fact popping up everywhere, hierarchy reerecting its comforting structure in all these new provincial settlements, Mercury, the asteroids, the outer systems — everywhere except on noble Mars.

Here on Mercury it was particularly bad. Meetings between the Martian delegation and the Mercurians had been going on in Terminator for weeks, and Zo was tired of them, both the meetings and the Mercurial negotiators, a secretive self-important group of oligarchic mullahs haughty and fawning at the same time, who had not yet comprehended the new order of things in the solar system. She wanted to forget them and their little world, to go home and fly.

On the other hand, in her cover as a lowly staff assistant she had up to this point been an entirely minor figure in the proceedings, and now that negotiations were grinding to a halt, stalled on the stubborn incomprehension of these happy slaves, her turn had come at last. As the meeting broke up, she took aside an aide to the highest leader in Terminator, who was called rather picturesquely the Lion of Mercury, and she asked the aide for a private meeting. The young man, an ex-Terran, was agreeable — Zo had made sure of his interest long before — and they retired to a terrace outside the city offices.

Zo put a hand to the man’s arm, said kindly, “We’re very concerned that if Mercury and Mars don’t make a solid partnership, Terra will wedge between us and play us off against each other. We’re the two largest collections of heavy metals left in the solar system, and the more civilization spreads, the more valuable that becomes. And civilization is certainly spreading. This is the Accelerando, after all. Metals are valuable.”

And Mercury’s natural fund of metals, though hard to mine, was truly spectacular; the planet was only a little bigger than Luna and yet its gravity nearly equaled that of Mars, a very tangible sign of its heavy iron core, and its accompanying array of more precious metals, seamed all through the meteor-battered surface.

“Yes … ?” the young man said.

“We feel that we need to establish a more explicit…”

“Cartel?”

“Partnership.”

The young Mercurian smiled. “We aren’t worried about being pitted against Mars by anyone.”

“Obviously. But we are.”

For a time there, at the beginning of its colonization, Mercury had seemed to be very flush. Not only did the colonists have metals, but being so close to the sun, they had the possibility of tapping a great deal of solar energy. Just the resistance set up between the city’s sleeves and the expanding tracks they slid over created enormous amounts of it, and there was even more in solar-collection potential; collectors in Mercurial orbit had started lazing some of that sunlight out to the new outer-solar-system colonies. From the first fleet of track-laying cars, in 2142, through the rolling construction of Terminator in the 2150s, and throughout the 2160s and 70s, the Mercurians had thought they were rich.

Now it was 2181, however, and with the successful wide deployment of various kinds of fusion power, energy was cheap, and light was reasonably plentiful. The so-called lamp satellites, and the gas lanterns burning in the uoper atmospheres of the gas giants, were being built and lit all over the outer system. As a result Mercury’s copious solar resources had been rendered insignificant. Mercury had become once again nothing more than a metal-rich but dreadfully hot-and-cold place, a hardship assignment. And unterraformable to boot.

, Quite a crash in their fortunes, as Zo reminded the young man without much subtlety. Which meant they needed to cooperate with their more conveniently located allies in the system. “Otherwise the risk of Terran return to dominance is very real.”

“Terra is too enmeshed in its own problems to endanger anyone else,” the young man said.

Zo shook her head gently. “The more trouble Terra is in, the worse danger for the rest of us. That’s why we’re worried. That’s why we’re thinking that, if you don’t want to enter into an agreement with us, we may just have to build another city and track system on Mercury, down in the southern hemisphere, and cruise in the terminator down there. Where some of the best metal deposits are.”

The young man was shocked. “You couldn’t do that without our permission.”

“Couldn’t we?”

“No city on Mercury can exist if we don’t want it to.”

“Why, what will you do?”

The young man was silent.

Zo said, “Anyone can do what they want, eh? This is true for everyone ever born.”

The young man thought it over. “There’s not enough water.”

“No.” Mercury’s water supply consisted in its entirety of small ice fields lying inside craters at the two poles, where they remained in permanent shadow. These crater glaciers contained enough water for Terminator’s purposes, but not much more. “A few comets directed at the poles would add more, however.”

“Unless their impact blasted all the water on the poles away! No, that wouldn’t work! The ice in those polar craters is only a tiny fraction of the water from billions of years of comets, hitting all over the planet. Most of the water was lost to space on impact, or burned off. The same thing would happen if comets struck up there now. You’d get a net loss.”

“The AI modelers suggest all kinds of possibilities. We could always try it and see.”

The young man stepped back, affronted. And rightly so; you couldn’t put a threat much more explicitly than that. But in slave moralities the good and the stupid tended to become much the same, so one had to be explicit. Zo held her expression steady, though the young man’s indignation had a commedia dell’arte quality that was quite funny. She stepped closer to him, emphasizing their difference in height; she had half a meter on him.

“I’ll give the Lion your message,” he said through his teeth.

“Thanks,” Zo said, and leaned down to kiss him on the cheek.

These slaves had created for themselves a ruling caste of physicist-priests, who were a black box for those on the outside, but like all good oligarchies predictable and powerful in their exterior action. They would take the hint, and be able to act on it. An alliance would follow. So Zo left their offices, and walked happily down the stepped streets of the Dawn Wall. Her work was done, and so very likely the mission would soon return to Mars.