“Rather than figure it was a Western Union express to me from the Man Upstairs?” Evers turned to him again, rolled his eyes heavenward. “Got that right, my friend.”

Nimec smiled, went back to looking out the window. He was still trying to adjust his sense of scale.

Evers noted his expression.

“The sprinkles of white around the bergs are mostly pancake ice mixed in with growlers . . . slabs the size of cars,” he said. “Proportions are deceptive from this altitude in the best of circumstances, and impossible to judge in poor weather. It’s why fog and overcast concern us as much as flying snow. When the sunlight’s refracted between a low cloud ceiling and snow or ice cover on the ground, everything blends together, and there’s no sight horizon.”

“Zero visibility,” Nimec said. “I’ve gotten stuck driving in blizzards more than once. Feels like there’s a white blanket across the windshield.”

At his station, the navigator shifted toward Nimec. The blue laminate name tag on his breast identified him as Lieutenant Halloran.

“It isn’t quite the same,” he said. “Any flier will tell you there’s no worse pain in the ass than getting stuck in a fog whiteout.”

Nimec looked at him, thinking his tone was a bit too purposefully casual.

“If there’s a heavy snow alert, you know to stay wheels-down until the storm passes,” Halloran said. “But say you’re airborne over the ice and hit a fog bank. Around the pole it can happen just like that.” He snapped his fingers. “The way our eyes and brains are wired, we use shadows to judge the distance of things on a uniformly white field—and in a whiteout you lose shadows. So even if the air’s dry under the clouds and you’re able to see an object, the perspective may be false. No, scratch that . . . it will be false. With winter around the bend, you have to be especially careful because the sun’s inclination isn’t very high regardless of the time of day.”

“Meaning it won’t cast much shadow.”

“That’s right. Unless you’re keeping a close check on your instruments—and sometimes even then—you can get disoriented, fly upside down without realizing it, smash into the ground while you think you’re still a mile up. Or drop off the edge of a cliff if you’re on foot. Happened to some of Scott’s men. Around the turn of the last century, wasn’t it, Chief?”

Evers nodded. “The Discovery expedition.”

Halloran looked pleased with himself.

“And isn’t just humans that are affected,” he went on. “You know what a skua is?”

Nimec shook his head.