Fresh snow had completely covered their tracks made during the climb to the summit, but they wouldn't have followed the same trail back down in any case. Both men were expert skiers and they cut back down the shortest route to the Sno cars. A faint audio signal sounded in their right ears from the homing beacons in the snow vehicles. As they shifted directions through the trees, the signal shifted from ear to ear and grew stronger as they neared their cache. A few minutes later they broke out into the edge of the small clearing with its downed spruce and the two Sno cars. From the carriers they extracted light-weight collapsible plastic domed shelters. A half hour later the domes were joined together by a two-man shelter tube and their sleeping bags were spread in the rear dome. While Alec was shaking out the bags and stowing gear, Troy set up the tiny camp stove in the front dome, broke out the rations and began supper. The detachable, mercury-battery headlight from one of the Sno cars hung from the apogee of the front dome and the other car light was in the sleeping dome. By the time they had finished eating, the wind had died but the snow continued to fall, piling up around the outside of the plastic dome as it drifted and fell. Its sheltering bulk added to the already near-perfect insulation of the domes. The outer air temperature had fallen to minus fifteen degrees but the temperature below the surface of the snow held at a constant twenty-five degrees above zero and within the front dome with its light and stove, it was a warm seventy-five. The excess heat escaped through a flue tube in the top of the dome. Both men had stripped down to shorts and T-shirt and now quietly relaxed. "That's a goodly amount of precip piling up out there," Alec remarked languidly. "God knows we can use it." "If this keeps up all night," Troy said, "we may have to dig ourselves outta here in the morning." He leaned back and surveyed the rounded roof above him. "Remember what I said this afternoon about nothing ever changing in DivAg?" Alec nodded. "Well, sir, here's another fine example of progress halted dead in its tracks," the lanky hydrologist went on. "For centuries the Eskimos have lived through Arctic winters in igloos, made of snow blocks, cut and rounded to form a cave in the snow. "What's good enough for the Eskimos is good enough for DivAg. Here we are right back in the Ice Age, living in an igloo. If that stove used blubber or seal oil instead of chemical fuel, the picture would be complete." Alec grinned. "Just because something is old doesn't mean it's no good, Dr. Braden," he said. "The Eskimos proved the efficiency of the igloo. We've just adopted the principle and modernized it. It still works better than any other known snow-weather shelter. But I didn't see you cutting any snow blocks with your skinning knife to build this snug haven, nor crawling for hours on your belly across the snow to sneak up on a seal for your supper."