“You figure right, Pete.” Meg swiveled in her chair, faced the map, and pointed. “The yellow one shows where they struck camp. It’s where McKelvey Valley crosses the northern mouth of Bull Pass. See?”

He nodded.

“The red pin would be about four miles from the camp-site, straight down into the pass,” she said. “That’s where they were last sighted.”

“By whom?”

“A chopper pilot named Russ Granger. He’s been at McMurdo forever, makes regular air runs to its research bases in the valley system.”

“He have any contact with the team?”

“No,” she said, and then thought a moment. “Well, let me revise that. They did exchange hellos. But it was just a fluke that Russ passed over Scarborough and the others at all.” She paused. “He says they seemed perfectly fine to him.”

“When would that have been? The time of day, I mean.”

“Ordinarily we’d be entering vague territory. But I think I know where you’re heading, so let me put my answer in context,” she said. “Time measurement becomes almost arbitrary when the whole year’s roughly divided into six months of daylight, and six months of darkness. Most stations set their clocks to match up with a time zone in their home countries for ease of communications . . . though that can lead to chaos when they have to make arrangements with other bases. Here at Cold Corners we’ve opted for Greenwich time simply because that’s what they use at MacTown, and there’s considerable interaction between us.”

“Then whatever time it was for Scarborough’s group would’ve corresponded with the pilot’s.”

“Yes,” Megan said. “Russ was heading to Marble Point.” She gestured toward its position on the Dry Valleys map. “That’s a little refueling facility at the foot of the Wilson Piedmont Glacier, about fifty miles northwest of McMurdo. He’d made the first two stops of his shift, and thinks it was about seven A.M. when he saw our party.”

“And your best guess about how long they’d been out on foot . . . ?”

“Two hours at most. The area they covered had some tedious rocky patches, but Scarborough would have left camp early.”

“Old military habit?”

She nodded. “He isn’t the type to waste a minute.”

Nimec contemplated that, peering at the map.

“They were just getting started,” he said.

“Yes.”

“What about after the pilot saw them that morning? They report in to Cold Corners at any point?”

Meg was shaking her head now.

“That would have been largely at their discretion. Of course we’d have expected to hear from them if they located the rover. Obviously if they needed assistance. But we never received a Mayday. It’s the part that drives me crazy, Pete . . . trying to understand why Scar wouldn’t have let us know he was in trouble.”

“Had me and the boss wondering too.” Nimec rubbed his chin. “Any chance I could talk to the pilot myself?”