Energy cascaded up through the radiative zone, releasing some of the pent-up energy in that million-year storage tank into the bargain. And, two-thirds of the way to the surface of the sun, these energies reached the tacholine: the frontier between radiative and convective zones, above which point the substance of the sun boils like water in a pan. The tacholine was the place where the sun’s active regions had their deepest magnetic roots. And it was into the tacholine, this troubled border, that the core’s oscillations vented their anger.

Sun-girdling flux tubes writhed like snakes, and immediately began to rise. Normally it would take months for a flux loop to reach the sun’s surface. But these mighty toroids, shouldering aside the cooler plasma above, took only days. And such was the disturbance in the sun’s deeper layers that energy poured after the loops, like air escaping from a balloon.

Even in quiet times, loops of magnetic flux breach the sun’s surface. They form a carpet above the photosphere, a weaving of loops and patches and fibrils of plasma. The smallest of such loops is immense on the scale of Earth. The loops that arose now were monstrous, rising high above the sun’s surface, dragging plasma streams behind them. This huge magnetic disruption interfered with the flow of energy from the sun, and for a time the area at the base of this forest of magnetism, starved of energy, actually grew darker than the rest of the star. Human eyes and instruments saw an immense sunspot region blossom across the sun’s shining face.

The loops that protruded above the surface were like trees packed together, with roots buried deep beneath the photosphere. The loops braided, twisted, jostled, and sheared as they tried to shed energy and find a new equilibrium. At last, at the heart of this writhing forest, two loops crossed like wizards’ wands. The loops merged and snapped. The release of energy into the surrounding forest was catastrophic, driving currents of plasma to a frenzy, and in turn driving the other loops to further thrashing. Soon there were more reconnections all across the continent of disturbance.

The magnetic forest delivered up its energy in a cascade of events, and a great pulse of hard X-rays, gamma rays, and high-energy protons gushed out into space.

This was a titanic event—but it was just a solar flare, though an immense one, a flare created by the processes by which a restless sun had always shed its energy. What followed was unprecedented.

The immense sunspots beneath the magnetic forest began to break up. Through the deep wound burrowed into the sun’s flesh two thousand years before, a harder light began to shine. Soon the sun would shed, in a few hours, energy that could have kept it shining for a year.

Just as had been planned, far away and long ago. It was April 19, 2042.

34: Sunset (I)

Bisesa woke.

She sat up, rubbing at her shoulder. She had been napping on the sofa in the living room of her flat. While she had been asleep the flat had grown dark.

“Aristotle. Time, please.”

To her surprise he didn’t give her a clock time in response. Instead he said: “Sunset, Bisesa.”

This was April 19, the day before the sunstorm itself. And so this was the last sunset.

On the Moon, Eugene was predicting that the storm would break during the night, at about three British time. So the far side of the planet would suffer the storm’s initial effects. But the world would turn as it always did, and over Britain the sun would rise.

Things would be different in the morning.

She shivered. “Even now it doesn’t seem real,” she said.

“I understand,” Aristotle said.

Bisesa made her way to the bathroom and splashed water on her face and neck. The flat was empty. Myra was evidently out somewhere, and Bisesa’s cousin Linda had moved back to Manchester to be with her immediate family during the storm.

She thought over Aristotle’s simple phrase: “I understand.” Aristotle was a being whose electronic senses were distributed over the whole planet and beyond, and everybody knew that his cognitive powers far exceeded any human’s. Surely his level of understanding of what was to come far outstripped hers—and in a sense Aristotle was in as much personal danger as she was. But she couldn’t think of a thing to say to him about it.

“So where’s Myra?”

“Up on the roof. Would you like me to call her down?”

She glanced out uneasily at the gathering dark. “No. I’ll go get her. Thanks, Aristotle.”

“My pleasure, Bisesa.”

She took the staircase to the roof. The Mayor’s office had made fulsome promises that disruption to power supplies would be kept to the minimum possible, but Bisesa already distrusted lifts and escalators. And besides, according to the emergency authority’s latest decree, all such gadgets were to be shut down at midnight anyhow, and all electronic locks fixed on open, to avoid people being trapped when the hammer blow fell.

She reached the roof. The Dome stretched over the rooftops of London, with deep blue rectangles of sky showing where the last panels had yet to be closed. As the Dome’s immense roof had been closed off, stage by stage, it had felt increasingly as if they were all living in a vast cathedral, she thought, a single huge building.

As the regular cycle of day and night had become less marked, Bisesa wasn’t the only one whose sleep pattern was disrupted, according to Aristotle; other sufferers ranged from the Mayor herself to the squirrels in London’s parks.

On the roof, Myra was lying on her belly on an inflatable mat. She was working on what looked like homework, on a softscreen tiled with images.

Bisesa sat beside her daughter, cross-legged. “I’m surprised you have work to do.” School had been out for a week.

Myra shrugged. “We’re all supposed to blog.”

Bisesa smiled. “That’s a very old-fashioned idea.”

“If a teacher wasn’t old-fashioned you’d be worried. They even gave us pads of paper and pens for when the softscreens get fritzed. They said, when historians write about what happens tomorrow, they will have all our little viewpoints to put in.”

If there are any historians after tomorrow, Bisesa thought. “So what are you writing?”

“Whatever hits me. Look at this.” She tapped a corner of her softscreen and a small tile magnified. It showed a ring of monolithic stones, a gathering of white-robed people, a handful of heavily armed police.

“Stonehenge?” Bisesa asked.

“They’re there for the last sunset.”

“Are they Druids?”

“I don’t think so. They’re worshiping a god called Sol Invictus.”

Everybody had become an expert on sun gods. Sol Invictus, the Unconquered Sun, was one of the more interesting of his breed, Bisesa thought. He had been one of the last of the great pagan gods; his cult had flourished in the late Roman Empire just before Christianity had become the state religion. To Bisesa’s disappointment, however, there had been no trace of anybody reviving Marduk, the Babylonian god of the sun. “It would be nice to see the old guy again,” she had said to Aristotle, to his confusion.

Myra said, “Of course there’s no Dome over Stonehenge. I wonder if the stones will be standing tomorrow. In the heat, they might crumble and crack. That’s a sad thought, isn’t it? After all these thousands of years.”

“Yes.”

“Those sun botherers say they will be there for sunrise too.”

“That’s their privilege,” Bisesa said. Tonight the world had more than its fair share of crazies, preparing to use the storm to commit suicide in a variety of more or less ingenious ways.

Bisesa was distracted by a distant crackle, what sounded like shouting. She stood up, walked to the edge of the roof, and looked out over London.