He said, “It goes back to the work of Cowling in the 1930s. Cowling showed that the rate of nuclear energy generation in the core is dependent on the fourth power of temperature. Which makes conditions in the core of the sun extremely sensitive to temperature changes …”

He was right, Siobhan realized uneasily. That fourth-power factor would lead to even small changes being magnified. Huge as it was, the core wasn’t necessarily stable at all, and any small perturbation could disrupt it significantly.

Bud Tooke interrupted with a raised finger. “I don’t get it, Eugene. So what? Even if the whole core explodes, it would take megayears for the bang to work its way out to the surface.”

Rose Delea grinned sourly. “Don’t tell me. The radiative layer is screwed too, right?”

She was correct; another of Eugene’s images showed it. That great tank of slow-propagating energy was flawed by a puckered scar, like a wound stitched through flesh by a bullet. And so, Siobhan realized uncomfortably, the million-year lagging around the core wouldn’t work as a protective layer: any energy released in the core could be squirted straight out to space.

Eugene looked at Rose, puzzled. “How did you know about the flaw?”

“Because this is turning out to be that kind of day.”

Eugene talked on about his models of the core oscillations, and how he was hoping to run them back in time. “I’m intending to develop models of the inciting event of this instability, which—”

“Never mind the past for now,” Siobhan interrupted. “Look forward. Show us what’s to come.”

Eugene seemed puzzled that the future should even be of interest compared with the deep physical mystery of the origin of this anomaly. But he obediently ran his graphic forward in time, at an accelerated pace.

Siobhan could see that the wave propagation through and around the core was complex, with multiple harmonics added to the base oscillations, and waves that were nonlinear, as the specialists would say, with energy leaking from one mode into another. But she immediately saw that there were patterns of interference, of dissipation—and, more ominously, of resonance, when the energy she could so clearly see flowing around the core of the sun gathered into powerful peaks.

Eugene froze the image. “Here’s the most recent spike, the June 9 event.” One side of the core was flaring bright with false color. “The observational data confirms my preliminary modeling, and validates my future projections …” By observational data, Siobhan thought ruefully, he meant a devastating storm that had cost thousands of human lives.

She asked, “And what’s to come?”

He ran the model forward at a greater pace. The patterns of oscillation shifted and swam in Siobhan’s vision, too rapid to follow in detail.

Then, suddenly, the image flared bright, all over the core, almost bright enough to dazzle. People flinched, briefly shocked.

Eugene shut down his graphics. He said laconically, “That’s it.”

Rose Delea said dangerously, “What do you mean, that’s it?”

“At this point the model breaks down. The oscillations become so large that—”

“Your damn model!” Delea shouted. “Is that all you can think about?”

“Let’s take it easy,” Siobhan said, thinking fast. “Eugene, we’re looking at another event here. Correct? Another June 9.”

“Yes.”

“But more energetic.”

He looked at her, puzzled by her ignorance once more. “That’s obvious.”

Siobhan glanced around the table, at wide-eyed, uncomfortable faces. Evidently Eugene hadn’t shared these results with anybody before, not even Mikhail.

Bud asked, “How much more? And how will it manifest itself? How will it hit us, Eugene?”

Eugene tried to answer, but he descended quickly into technicalities.

Mikhail laid a hand on Bud’s arm. “I don’t think he can say. Not yet. I’ll work with him on it.” He went on thoughtfully, “But you know, this isn’t unprecedented. We might be looking at another S Fornax.”

“S Fornax?”

For decades the astronomers had been studying middle-aged stars of the sun’s class, and on many of them had noticed cycles of activity similar to the sun’s. But some stars showed rather more variability than others. An unspectacular star in the constellation called Fornax had suddenly flared up one day, shining twenty times as bright as usual, for maybe an hour.

Mikhail said, “If the sun erupted like S Fornax, the energy input would have been something like ten thousand times as bad as our worst solar storms.”

“And what would that do?”

Mikhail shrugged. “Disable the whole satellite fleet. Destroy Earth’s ozone layer. Melt the surfaces of the ice moons—”

Siobhan remembered dimly that the constellation name, Fornax, meant “furnace.” How appropriate, she thought.

But Eugene actually laughed. “Oh, this core nonlinearity will be much more energetic than that. Orders of magnitude worse. Don’t you even see that much?”

That crack brought him looks of resentment, even hatred.

Siobhan studied him, baffled. It was as if all this were no more than a mathematical exercise to him. He was just a boy who saw patterns, she thought, patterns in the data; the patterns’ meaning in human terms was invisible to him. She felt almost frightened of him.

But she must concentrate on what he had said, not the way he said it. Orders of magnitude. To a physicist, indeed to a cosmologist, an order of magnitude meant a factor of ten. So whatever was coming would be ten, a hundred, a thousand times worse than June 9, worse even than this S Fornax event of Mikhail’s. Her imagination quailed.

And there was one obvious question that had yet to be asked. “Eugene, do you have a date for this event?”

“Oh, yes,” Eugene said. “The model’s already good enough for that.”

“When, Eugene?”

He tapped at his softscreen and gave a date in Julian days, an astronomer’s date. It took Mikhail to translate it into human terms.

“April 20, 2042.”

Bud looked at Siobhan. “Less than five years.”

Suddenly Siobhan felt hugely weary. “Well, I guess I’ve found out what I came here to know. And maybe now you can see the need for security.”

Rose Delea snorted. “Security, my arse. We could all run around naked with bags on our heads for the next five years and it wouldn’t make any difference. You heard him. We,” she said concisely, “are fucked.”

Bud said firmly, “Not if I can help it.” He stood up. “Lunchtime. I guess you might want to call your Prime Minister, Siobhan. Either of them. Then we get back to work.”

14: Missing in Action

Too soon, time ran out for Bisesa.

Myra’s school reopened. The headmistress understood that for some families, bereaved, displaced, shocked, or simply frightened, more recovery time was needed. But as the weeks wore by a note of insistence crept in. Disaster or no disaster, the education of the young had to go on: that was the law, and it was up to parents to fulfill their obligations.

For Bisesa, the pressure was mounting. She was going to have to release Myra before the social services came looking for her. The cocoon she had built around the two of them was starting to crack.

But it was the British Army that finally broke her out into the daylight. Bisesa received a polite e-mail asking her to report in to her commanding officer.

As far as the Army knew Bisesa had simply disappeared from her posting on June 8, before the solar storm, and her five-years-too-old ident chip making her untraceable, she had not been heard of since. In the immediate aftermath of the storm, the Army, in Afghanistan and elsewhere, had had other things to think about. But now the service’s bureaucratic patience was running out.