When he raised his trunk that way he could smell water: fresh water, a vast body of it, beyond that cleft in the rock.
The mammoths discussed this briefly. The ice wedge was less than a day’s walk away, and if there was water to be had the detour was surely worth the investment of their time. And besides, Longtusk admitted to himself, he was piqued by curiosity; he would like to know the story of this distorted, damaged land.
They followed one of the wider channels toward the ice plug, their muscles working steadily as the land rose.
At last Longtusk topped a ridge of rock, and he was able to look beyond the cleft and its plug of ice.
There was a lake here. It was broad and placid, and it lay in a natural hollow in the land. The water was fringed by rock and ice: the plug of ice that barred it from the damaged lands to the south, and by the shrinking icecap which lay at its northern end.
The mammoths walked cautiously down to the lake’s gravel-strewn fringe. The water was ice cold, but they sucked it into their trunks gratefully. Threetusk and the young Cows splashed out into the water, playfully blowing trunkfuls of it over each other. After a time they loped clumsily out of the water, their breath steaming, their outer fur crackling with frost.
Willow, too, made the best of the water. He threw off his furs and scampered, squat and naked, into the lake. He cried out at the cold, but immersed himself and scrubbed at the thick hair on his belly and head with bits of soft stone, getting rid of the insects that liked to make their homes there.
There seemed to be little vegetation in this placid pool. But there were signs of life by the shore, holes dug by rabbits and voles and lemmings in the long grass that fringed the water’s edge. And birds wheeled overhead, ducks and gulls.
"…But there are no fish here," said Rockheart. "Strange."
"But no fish could reach this place," Longtusk said thoughtfully.
At the lake’s northern shore, the ice gave directly onto the lake, making a cliff that gleamed white. There was a constant scrape and groan from all across the ice cliff, and Longtusk could see icebergs, small islands of blue-white ice, drifting away from the cliff. The lake water looked black beside the blinding white of the ice.
It was obvious that the ice was flowing from its mountain fastness, with hideous slowness, down toward the lake. And where the ice met the water the icebergs were calving off, great fragments of the disintegrating ice sheet.
In fact, Longtusk saw, the lake had been created by the melting of the ice sheet as it crumbled into this hollow in the rock.
"This lake is just a huge meltwater pond," Longtusk said, realizing. "It is fed by melting ice. There are no fish here, because there is no way for a fish to get here. And the water is kept from draining away by that—" The plug of ice in the rocky cleft on the lake’s southern side. "Fed by meltwater from the north, trapped by the ice plug to the south, this bowl in the land will gradually fill up—"
"Until," Rockheart growled, "that chunk of ice gives way."
"Yes. And then the lake will empty itself across the land, all at once — and wash away the soil and vegetation, scouring down to the bedrock."
Rockheart rumbled. "Like Kilukpuk’s mighty tears."
"Yes. No wonder the land is so damaged. But then the ice plug forms again, and the lake begins to fill once more."
Rockheart grunted. "If that’s true, we’re lucky. We’re in no danger here."
"What do you mean?"
"The water has some way to rise before it tops that ice dam."
"You’re right. We’ll be long gone by then." Good for Rockheart, Longtusk thought: practical as always, focusing on the most important issue — the mammoths’ safety.
They left the lake, calling to the others.
A few more days and he could sense the broadening of the land to north and south, and he knew they had passed the narrowest point of this neck of Earth that stretched between the continents.
Thus, the mammoths walked from Asia to America.
Soon after that he could see the icecap.
It was a line of light, straight and pure white, all along the eastern horizon, as if etched there by the ingenious paw of a Firehead. He could hear the growl and scrape as the ice flowed over the rocky land, gouging and destroying, the mighty cracks as the ice itself split and crumbled, and the steady roar of the blunt katabatic winds which spilled from its chill domed heart.
It was a frozen sheet that covered half a continent, pushing far to the south, much farther south than in the land they had fled, on the far side of the land bridge. And it was this monster of ice that they must challenge before they reached safety.
He tried to maintain the pace and enthusiasm of his little group. But as they drew closer he could feel his own footsteps drag, as if the icecap itself was drawing out his strength, just as it sucked the moisture from the air.
They reached land that had clearly been uncovered only recently by the ice.
The rock was scoured clean, laced here and there with low dunes of glacial till and sand. Only lichen grew here: patches of yellow and green, bordered by black, slowly eroding the surfaces of the rock. The lichen might be extremely ancient; it took ten years for a new colony to become visible to the eye. He wondered what slow encrusting dreams these vegetable colonists shared, what slow cold memories of the surging ice they stored.
The land became steadily more treacherous. They worked their way past moraines, heaps of rubble left by the retreating ice. The rubble was of all sizes, from gritty sand to boulders larger than a mammoth. The moraines were cut through by meltwater rivers that varied unpredictably from trickles to mighty, surging flows, and the rubble heaps were unstable, liable to slump and collapse at any time.
As they pressed farther, a great wind rose, katabatic, pouring directly off the ice sheet and into their faces. It was a hard time. There was little to eat or drink and every step required a major effort, but they persisted. And Longtusk was careful to encourage his charges to gather as much strength as possible, for he knew that only harder days, if anything, lay ahead of them all.
At last they encountered the ice itself.
They reached the nose of a glacier. It was a wall of ice, cracked and dirty and forbidding. Blocks of broken ice, calved off the glacier like miniature icebergs, lay unmelting on rock that was rust-red, brown and black. Tornado-like columns of ice crystals spun across the barren rock in the wind, whipping up small lumps of sandstone that flew through the air, peppering the mammoths’ hides.
This was the terminus of a huge river of ice that poured, invisibly slowly, from the vast cap that still lay to the east.
The mammoths paused to gather breath, hunted without success for food, and then began the ascent.
Longtusk picked his way onto the great ice river, stepping cautiously over a shattered, chaotic plain of deeply crevassed blue ice. The glacier was a river of raw white, its glare hurting his eyes, shining under the sky’s clean blue. He could see the glacier’s source, high above him, at the lip of the ice sheet itself. Where he could he chose paths free of crevasses and broken surfaces, but he could usually find easier ground near the glacier’s edges, hugging the orange rock of the valley down which the glacier poured.
It was difficult going. Sometimes loose snow was whipped up by the wind and driven over the surface, obscuring everything around him up to shoulder height. But, above the snow, the sky was a deep blue.
At last the ice beneath his feet leveled out, and he realized he had reached a plateau.
It was the lip of the ice sheet.