“You getting tired?” Lantos asked. “We could take a break.”

But Slater wanted to press on. His stamina was not what it was, and he feared that he could have a malarial chill at any moment; better to keep at it while his hand was reasonably steady and take a break only if he had to. “I’ll take the Stryker saw,” he said, and Lantos handed it to him. The air behind his face mask was warm and uncomfortably moist.

As she made sure that the skin and stray hairs stayed clear of the blade, Slater methodically sawed a circular cap, the size of a beret, from the very top of the skull. Once the cut was complete, he put the saw down and jiggled the section he had cut. In a couple of spots, it still held firm to the rest of the head, and he had to go back with his scalpel and pry the connective tissue or bone loose. If he were back in med school, he’d have just earned a C.

Then, as Lantos held a clean basin under the back of the head, he lifted the cap free and she put it out of the way.

The brain was now completely exposed; the dura mater, normally white, was the color of strong tea. Slater picked up a pair of forceps, his wet fingers almost letting them slip, as Eva took the lid off a container of formalin — a 15-percent solution of formaldehyde gas in buffered water that would be used to preserve the brain samples long enough to get them back to the labs in Washington — and held it out.

Suddenly, the overhead light waned, then brightened, then waned again.

Slater’s gaze met Lantos’s.

The light flickered.

It was the generator, he thought. It couldn’t be anything else.

The light went out, then on, then out again.

The backup generator was kicking in, sensing a break in the current, and coming online. His eyes flew to the freezer vault on the floor of the chamber — the one containing the first specimens taken in the open grave. But then he noticed Lantos looking through the plastic barriers of the chamber and out at the tent walls, which appeared to be undulating in the wind … but undulating in color.

What the hell?

The flaps of the main lab area flew open, and through the distortion of the plastic sheathing, Slater could make out a figure — moving small and fast — toward the autopsy chamber. Nika.

“It’s okay!” she hollered, even as Slater shouted, “Don’t come in here!” The biohazard warning insignia — an orange triangle — should have been enough, but Nika was the kind of woman who might race right through it.

“What’s going on?” Slater said.

“It’s the northern lights!”

“I mean what’s happening to the power!”

“The northern lights!” she repeated, impatiently waiting just outside the chamber. “The aurora borealis! It screws up the electrical fields every time.”

The walls of the tent were glowing a faint gold.

“You go,” Lantos said, “I’ll finish up in here.”

“Absolutely not,” Slater replied, but Lantos held firm.

“We’ve done all we can do in one session, anyway,” she said.

“We’ve got the brainpan to excavate.”

“It can wait,” she replied. “To be honest, Frank, your hand isn’t as steady as it needs to be. I was wondering when to tell you. You need to take a rest.”

Slater was surprised that she would say so, but he was willing to concede that she might be right. He’d been pushing it, and any minute he might have made a terrible mistake. He’d made the right choice in recruiting her for this mission.

“Thanks,” he said. “Point taken.”

After warning Nika to wait for him outside the tent, he stripped off the hazmat suit and protective gear, depositing them all in the safety bin. Then, after a quick scrubdown in the lab, he grabbed his coat off the hook by the entrance and joined her in the fresh air.

The sky was still swarming with strange shapes and colors. Taking his hand like an enthusiastic kid at the zoo, Nika tried to drag him down toward the colony gates, but first Slater had to make a detour to the generator shed, the snow and ice crunching under his boots, to make sure the machinery was still functioning. Rudy the Coast Guardsman was already inside, keeping a close watch on the twin turbines and their myriad gauges.

“Has the current been uninterrupted?” Slater asked urgently.

“Except for a couple of hiccups, and for no more than a second or two each time,” Rudy replied, “it’s been okay.”

Slater breathed a sigh of relief even as the cell phone in his pants pocket suddenly rang, buzzed, and by the time he took it out, went dead.

“The aurora gives off a really strong electromagnetic charge,” Nika said sympathetically. “You probably just lost your address book and emails.”

“Let me know if either one of the generators goes down for more than a minute,” Slater said, and Rudy, not taking his eyes off the machinery, signaled that he would.

Stepping out of the shed again, Slater let himself be led down to the cliffs, where Sergeant Groves and Kozak were already occupying ringside seats, gazing out over the black expanse of the Bering Strait. A curtain of shimmering lights — green and yellow, purple and pink — were swirling and curlicuing in the air, hovering maybe sixty or seventy miles above the water and extending high into the sky.

“The solar flares are putting on quite a show for us tonight,” Kozak said, acknowledging Slater and Nika by cocking his pipe in their direction. The cherry tobacco perfumed the air.

“Solar?” Groves said. “We haven’t seen the sun for more than three hours all week.”

“The solar wind takes two days to reach us, and when the flood of electrons and protons hits the upper atmosphere, they collide with the atoms there, and go boom!” He took another puff on his pipe. “This collision gives off radiation in the form of light. Different atoms give off different colors. In Mongolia, I once saw them turn to a scarlet red. But that is very rare.”

“Yeah, well, these will do just fine,” Groves said, staring up at the pulsating veil of green and yellow bands performing elaborate arabesques in the sky. “You don’t catch anything like this in Afghanistan.”

Slater, too, was impressed — he’d never seen the aurora borealis — but the sparkling green lights bathing the horizon made him think, oddly enough, of that hellish sight on CNN, on the night the United States had initiated its much-vaunted “shock and awe” attack on Baghdad. He’d known that much of America was sitting in front of its TV sets, filled with that strange, guilty exultation that comes with war and displays of military might; when he was young and unthinking, he’d felt that way himself. But his own heart had sickened at the thought of what he knew was happening there on the ground. He had been dispatched to far too many such places in the aftermath of war, places where nothing remained standing and everything from cholera to typhus ran riot. He was aware of the human toll that was being taken before his very eyes.

“For the Native Americans,” Nika said, “the northern lights were considered a ladder to heaven.”

“I can see why,” Groves readily assented.

“Whenever they saw the lights, they thought they were looking at the spirits of their ancestors dancing and playing games as they ascended to the next world.”

“Maybe they had it right,” Groves said.

“It certainly beats the funerals in Russia,” Kozak said, solemnly. He tamped at his pipe and appeared lost in thought.

While they had all bundled up against the freezing wind, Slater noticed that Nika’s coat was loosely drawn around her, and her own long hair was streaming out like a mane. As she stood there beside him on the cliff, looking out toward the dwindling lights above the sea — the bands were swirling together now into a glowing lime-green corona — she looked so much like a natural part of this spectacle that it was no surprise to him she had returned from San Francisco to Alaska, or that she had been made a tribal elder of the Inuit people. He could see her ancestors in her.