This was called magnetostriction, Phillippa said. “The engineers know what’s happening. It’s just that the GICs today are bigger than anything they’ve seen before.”

“Phillippa—what’s a GIC?”

“A geomagnetically induced current.” Phillippa eyed Siobhan with suspicion, as if she shouldn’t have had to explain; perhaps she wondered if she was wasting her time. “We’re in the middle of a geomagnetic storm, Professor McGorran. A huge one. It came out of nowhere.”

A geomagnetic storm: of course, a storm from the sun, the same cause as the beautiful aurora. Siobhan, her brains clogged in the room’s gathering heat, felt dull not to have grasped this at once.

But her basic physics was coming back to her. A geomagnetic storm, a fluctuation of Earth’s magnetic field, would induce currents in power lines, which were simply long conductors. And as the induced currents would be direct, while the generated electrical supply was alternating, the system would quickly be overwhelmed.

Phillippa said, “The generating companies are wheeling—”

“Wheeling?”

“Buying in capacity from outside. We have exchange deals with France, primarily. But the French are in trouble, too.”

“There must be some tolerance in the system,” Siobhan said.

“You’d be surprised,” Toby Pitt said. “For fifty years we have been growing our power demands, but have resisted building new power stations. Then you have market forces, which ensure that every component we do install barely has the capacity to do the job that’s asked of it—and all at the lowest possible cost. So we have absolutely no resilience.” He coughed. “I’m sorry. A hobbyhorse of mine.”

“The worst single problem is the loss of air-conditioning,” Phillippa said grimly. “It isn’t even noon yet.”

In a 2030s British midsummer, heat was a routine killer. “People must be dying,” Siobhan said, wondering; it was the first time it had really struck her.

“Oh, yes,” Phillippa said. “The elderly, the very young, the frail. And we can’t get to them. We don’t even know how many there are.”

Some of the softscreens flickered and went blank. This was the other side of the day’s problems, Phillippa said: communications and electronic systems of all kinds were going down.

“It’s the satellites,” she went on. “The comsats, navigation satellites, the lot—all taking a beating up there. Even land lines are failing.”

And as the world’s electronic interconnectedness broke down, the smart systems that were embedded in everything, from planes to cars to buildings to clothes and even people’s bodies, were all failing. That poor man stuck in his hotel room had only been the first. Commerce was grinding to a halt as electronic money systems failed: Siobhan watched a small riot outside a petrol station where credit implants were suddenly rejected. Only the most robust networks were surviving, such as government and military systems. The Royal Society building happened still to be connected to central services by old-fashioned fiber-optic cables, Siobhan learned; the venerable establishment had been saved by its own lack of investment in more modern facilities.

Siobhan said uncertainly, “And this is another symptom of the storm?”

“Oh, yes. While our priority is London, the emergency isn’t just local, or regional, or even national. From what we can tell—data links are crashing all over the place—it’s global …”

Siobhan was shown a view of the whole world, taken from a remote Earth resources satellite. Over the planet’s night side aurorae were painted in delicate, heartbreakingly beautiful swirls. But the world below was not so pretty. Darkened continents were outlined by the lights of the cities strung along their coasts and the major river valleys—but those necklaces of lights were broken. As each outage triggered problems in neighboring regions, the blackouts were spreading like infections. Power utilities were in some places trying to help each other out, but, Phillippa said, there was conflict; Quebec was accusing New York of “stealing” some of its megawatts. In a few places Siobhan saw the ominous glows of fires.

All this in a couple of hours, Siobhan thought. How fragile the world is.

But the satellite imagery was full of hash, and at last it broke down altogether, leaving a pale blue screen.

“Well, this is dreadful. But what can I do?”

Phillippa again looked suspicious. You need to ask? “Professor McGorran, this is a geomagnetic storm. Which is primarily caused by problems with the sun.”

“Oh. And so you called an astronomer.” Siobhan suppressed an urge to laugh. “Phillippa, I’m a cosmologist. I haven’t even thought about the sun since my undergraduate days.”

Toby Pitt touched her arm. “But you’re the Astronomer Royal,” he said quietly. “They’re out of their depth. Who else are they going to call?”

Of course he was right. Siobhan had always wondered if her royal warrant, and the vague public notoriety that came with it, was worth the trouble. The first Astronomers Royal, men like Flamsteed and Halley, had run the observatory at Greenwich and had spent most of their time making observations of the sun, Moon, and stars for use in navigation. Now, though, her job was to be a figurehead at conferences like today’s, or an easy target for lazy journalists looking for a quote—and, it seemed, an escape route for politicians in a crisis. She said to Toby, “Remind me to quit when this is all over.”

He smiled. “But in the meantime …” He stood up. “Is there anything you need?”

“Coffee if you can get it, please. Water if not.” She raised her own phone to her face; she felt a spasm of guilt that she hadn’t even noticed it had lost its signal. “And I need to speak to my mother,” she said. “Could you bring me a land line?”

“Of course.” He left the room.

Siobhan turned back to Phillippa. “All right. I’ll do my best. Keep the line open.”

Dressed in recycled-paper coveralls, Mikhail and Eugene sat in Mikhail’s small, cluttered wardroom.

Eugene cradled a coffee. They were both awkward, silent. It seemed strange to Mikhail that such a handsome kid should be so shy.

“So, neutrinos,” Mikhail said tentatively. “Tsiolkovski must be a small place. Cozy! You have many friends there?”

Eugene looked at him as if he were talking in a foreign tongue. “I work alone,” he said. “Most of them down there are assigned to the gravity-wave detector.”

Mikhail could understand that. Most astronomers and astrophysicists were drawn to the vast and faraway: the evolution of massive stars and the biography of the universe itself, as revealed by exotic signals like gravity waves—that was sexy. The study of the solar system, even the sun itself, was local, parochial, limited, and swamped with detail.

“That’s always been the trouble with getting people to work on space weather, even though it’s of such practical importance,” he said. “The sun—Earth environment is a tangle of plasma clouds and electromagnetic fields, and the physics involved is equally messy.” He smiled. “We’re in the same boat, I suppose, me stranded at the Pole of the Moon, you stuck down a Farside hole, both pursuing our unglamorous work.”

Eugene looked at him more closely. Mikhail had the odd feeling that this was the first time the younger man had actually noticed him. Eugene said, “So what got you interested in the sun?”

Mikhail shrugged. “I liked the practical application. The sky reaching down to the Earth … Most cosmological entities are abstract and remote, but not the sun. And besides, we Russians have always been drawn to the sun. Tsiolkovski himself, our great space visionary, drew on sun worship in some of his thinking, so it’s said.”

“Maybe it’s because you don’t get to see much of it so far north.”

Mikhail was taken aback. Was that an actual joke? He forced a laugh. “Come,” he said, standing. “I think it’s time we visited the monitor room.”