They had rounded the corner and started down another barrackslike passage. Sully stopped at one of the doors, turned the knob, and pushed it open, revealing a spartan room with a cot, desk, wardrobe, and mirror. The worst of the dust had been cleared away by Chen earlier that morning. “These are your quarters,” Sully said.

Ekberg glanced inside quickly, then nodded her thanks as Sully and Marshall placed her bags on the cot.

“It’s a long ride up from New York,” Sully said, “and if you’re like us you probably didn’t get much sleep on the way. If you’d care to nap or freshen up, go right ahead. The showers and head are just down the corridor.”

“Thanks for the offer, but I’d better get started right away.”

“Get started?” Sully glanced at her in confusion.

Light dawned on Marshall. “You mean, you want to see it.”

“Of course! That’s why I’m here.” She looked around. “That is, if that’s all right with you.”

“I’m afraid it’s not all right,” Sully replied. “There have been several polar bear sightings in recent weeks. And those lava tubes are extremely dangerous. But you’re welcome to observe it from a distance, I suppose.”

Ekberg seemed to consider this. Then she nodded slowly. “Thank you.”

“Evan here will take you up-won’t you, Evan? Now, if you’ll excuse me, I have some tests I need to complete.” And with that he flashed her a faint smile, nodded to Marshall, then turned and made his way back in the direction of the temporary labs.

“Amazing,” Ekberg said, her words smoking the air. “I don’t think I’ve ever seen a sky such a clear, intense blue.”

They were making their way up the glacial valley in brilliant sunlight. Despite fretful allusions to the pressing nature of his work, Faraday had elected to come along, and he puffed and wheezed as they climbed. He’d been making this climb at least once a day for a month: the fact he still labored at it betrayed all his sedentary years spent in a laboratory. Ekberg, on the other hand, strode forward with the effortlessness of a committed runner. Her eyes darted everywhere, missing nothing. Now and then she would murmur something into a digital recorder. She was wearing Penny Barbour’s spare parka over her leather jacket.

“I know what you mean,” Marshall replied. “I just wish there was more of it.”

“Sorry?”

“The days are growing shorter, fast. We’ve got two, maybe three weeks of viable daylight left. After that, it’ll be white night around here, twenty hours a day. And we’ll be gone.”

“No wonder you’re in a hurry. In any case, Allan’s going to have a field day with that sky.”

“Allan?”

“Allan Fortnum, our DP. Director of photography.” She glanced ahead at the glacier, deep blue framing the sharp azure of the sky. “How did Mount Fear get its name?”

“After Wilberforce Fear, the explorer who discovered it.”

“Did that make him famous?”

“Actually, it killed him. He died of exposure at the base of the caldera.”

“Oh.” And Ekberg murmured something into the recorder. “Caldera. So it’s a volcano?”

“Extinct volcano. It’s quite a bizarre thing, really-the only geologic feature in a thousand square miles of permafrost. People are still arguing about how it formed.”

“Dr. Sully said it was dangerous. What did he mean by that?”

“ Mount Fear is really just a dead cone of prehistoric lava. Weather, and the glacier, have worn it down, made it fragile.” He pointed at the knife-edged ridges of the valley, then at one of the large caves that riddled the base of the mountain. “Lava tubes like that are created when a crust forms over an active magma stream. Over the years they become very brittle and can easily collapse. As a result, the mountain’s like a vast house of cards. We made the discovery in the back of one of those tubes.”

“And the polar bears he mentioned?”

“Cute to look at, but extremely man-aggressive, especially these days, what with habitat shrinkage. When your people get here, make sure they don’t stray beyond the fenced apron unless they’re armed. There’s a store of high-powered rifles at the base.”

They climbed a minute before Ekberg broke the silence again. “You’re a paleoecologist, right?”

“A Quaternary paleoecologist, yes.”

“And what, exactly, are you doing here?”

“Paleoecologists like me reconstruct vanished ecosystems from fossils and other ancient evidence. We try to determine what kinds of creatures roamed the earth, what they ate, how they lived and died. I’m determining what kind of an ecosystem existed here before the advance of the glacier.”

“And now that the glacier’s retreating, the evidence-the samples-are coming to light again.”

“Exactly.”

She looked at Marshall with penetrating, inquisitive eyes. “What kind of samples?”

“Plant traces. Layered mud. Some macro-organic remains like wood.”

“Mud and wood,” Ekberg said.

Marshall laughed. “Not sexy enough for Terra Prime, is it?”

She laughed in return. “What can you do with those?”

“Well, wood and other organics can be radiocarbon-dated to determine how long ago the glacier buried them. Mud samples are processed for pollen, which in turn indicates what kind of plants and trees were dominant prior to the glaciation. See, modern ecologists are stuck analyzing the world as it exists today, which has been hugely impacted by humans over the last hundred centuries. But with the samples, the readings, the observations I make here, I can reconstruct the world as it existed before humans became the dominant element.”

“You can recreate the past,” Ekberg said.

“In a way, yes.”

“Sounds pretty sexy to me. And I suppose a glacier’s the perfect place to do this because it would have locked everything into a deep freeze, preserving it like a time capsule.”

“Exactly right,” Marshall said. He was impressed by her ability to quickly size up and understand an unfamiliar discipline. “Not to mention the fact that when the ice melts, it simply releases its contents. No muss, no fuss-and no need for a lot of work with shovels and chisels uncovering fossils and subfossils.”

“A very pragmatic approach. What are subfossils? Really small fossils?”

Marshall had to laugh again. “That’s what paleontologists call fossils less than ten thousand years old.”

“I see.” She turned to the struggling Faraday. “And Dr. Faraday, you’re an evolutionary biologist, right?”

Faraday stopped to catch his breath, and the others halted obligingly. He nodded as he shifted his day pack from one shoulder to the other.

“And that means…?”

“Put simply, I study how species change over time,” Faraday puffed.

“And why are you doing it here, in such an inhospitable place?”

“My research involves the effect of global warming on species development.”

A smile formed on her face. “So you really are working on global warming. While Dr. Marshall, here, is simply taking advantage of it.”

Alarm bells rang faintly in Marshall ’s head: Terra Prime had funded their expedition with the understanding it would involve global warming. But Ekberg’s smile was a friendly one, and so he just smiled in return.

They stopped a moment so Ekberg could transcribe a few more notes. Marshall waited, looking out over the horizon. Then he paused. Plucking out his binoculars, he passed them to Ekberg. “Take a look. Out there on the permafrost, to the southwest.”

She peered through the glasses a moment. “Speak of the devil. Two polar bears.” She stared a minute, then passed the binoculars back. “Do we need to turn back?”

“We should be fine up here on the mountain. Normally, one of us would be armed.”

“So why aren’t we?”

“I refuse to carry a weapon. And Wright here is absentminded. Come on, we should get going.”

As they approached the glacier, Marshall looked up a little apprehensively at the glacial wall, but the recent frigid temperatures had arrested its retreat and the ice face looked much the same as it had three days ago when the cave was first exposed.