And nearby, under a thin layer of hoarfrost, they found a heap of mammoth dung. It was reasonably fresh, and hope briefly lifted; perhaps other Families were, after all, close.

But then Silverhair recognized the dung’s sharp scent. "Why, it’s mine," she said. "I must have come this way before."

Lop-ear broke open the pat of dung — it wasn’t quite frozen in the center — and began to lift chunks of it to his mouth. Mammoths will eat a little dung to sustain the colonies of bacteria that live in their guts, which help them digest grasses.

"Maybe our luck is changing, even so," he said around a mouthful of soil and dung.

"How?"

"Look up."

She did so, and she saw a curtain of light streaks spread across the sky — mostly yellow and crimson, fading to black, but here and there tinged with green. It extended from the horizon, all the way up the sky, almost to the zenith over their heads. The curtain rippled gently, like the guard hairs that dangle from the belly of a mammoth.

It was an aurora.

Mammoths believe the aurora is made up of the spirits of every mammoth who has ever lived, brought to life again by a wind from the sun, so joyous they dance at the very top of the air.

Lop-ear said, "What do you think? Is Longtusk up there somewhere, looking down on us? Do you think he’s come to guide our way?"

Indeed, the ghostly light of the aurora had made the Moonlit landscape glow green and blue, almost as brightly as day.

With uplifted hearts, they set off once more.

After days of walking they climbed a shallow ridge that gave them a view of the Island’s south coast, and Silverhair could see the pale blue-white gleam of pack ice on the sea. But between the two mammoths and the coast, lying over the land like a layer of guard hair, there lay the spruce forest. The first isolated, straggling trees were already close.

The two mammoths skirted the darker depths of the forest, staying at the northern fringe where only a few scattered, stunted trees encroached on the rocky tundra, ancient plants that grew no higher than their own bellies. It was well known that wolves inhabited the deeper forest. It was unlikely that even a pack would take on two full-grown mammoths, but inside the denser parts of the forest, movement would be difficult, and they would be foolish to offer the wily predators any opportunity.

The only sounds were the crunch of ice beneath their feet, the hiss of breath in their trunks, and the low moan of the wind in the trees. In the branches of a dwarf spruce a solitary capercaillie sat, unperturbed, eyeing them as they passed.

Night was falling by the time they reached the headland.

The sea opened up before them, flat and calm. A fringe of fast ice pushed out from the land, hard and glistening. Farther out, the sea ice was littered with trapped icebergs, sculptured mountains that glowed green and blue. Silverhair could see the rope of water that cut off the Island from the Mainland — which was, she saw, still shrouded by storm clouds that hid the glittering and mysterious array of lights that clustered there.

As the sun waned, the colors faded to an ice-blue twilight. The air grew colder, and the seawater steamed.

It was a bleak, frozen scene. But there was life here. More seabirds were arriving from the south, fulmars and black guillemots, and they had begun their elaborate courtship in the pink, watery sunshine. Seals slid through the open water, snorting when they broke the surface.

Beneath the headland was a valley that descended to the rocky southern coast. Silverhair and Lop-ear clambered down this valley.

Between the walls of the valley, nothing moved save an occasional swirl of dry snow crystals lifted by the wind. The mountainside here had been blown almost clear of snow, and in the shade the rock was covered by a treacherous glaze of ice. Their broad feet gripped the ground well; the round soles of Silverhair’s feet were thickened into ridges for that purpose. But even so her feet slid out from under her, and she barely managed to keep from stumbling. Once, she found herself teetering on the edge of a sheer drop into a snow-filled chasm.

Surrounded by these huge walls of ice and rock, Silverhair gained an unwelcome perspective on the smallness and frailty of even a mammoth’s life.

At last they reached the beach. It was growing dark, and they decided to wait out the long night there.

The beach was a strange place where neither of them felt comfortable.

For one thing, it was noisy compared to the thick stillness of the Arctic nights they were used to: they heard the continual lapping of the sea at the shingle, the crunching of stones beneath their shifting feet, the snapping and groaning of the sea ice as it rose and fell in response to the oily surges of the water beneath. There was no food to be had, for this eroded, shifting place was neither land nor sea. It was even considered a waste to pass dung here, for it would merely wash away to sea rather than enrich the land.

They endured a long, uncomfortable night of broken sleep.

The dawn, when at last it came, was clear. The sky turned an intense blue, and the sea ice was so white that the horizon was a firm line. As the sunrise itself approached, a shaft of deep red light shot suddenly straight up, piercing the blue. Silverhair looked out over the sea ice and saw that, thanks to a mirage effect, the distant pack ice seemed to be lifting into the sky, illusory towers rising and falling in the heat from the sun. And when the sun rose a little higher she saw a ghostly companion rise with it, a halo scattered by ice crystals in the air.

Lop-ear impulsively ran to the water’s edge. Breaking the thin ice, he waded in until his legs were immersed up to his hips and his belly hair was soaked and floating loosely on the surface.

He looked back at Silverhair. "Come on. What are you waiting for?"

Silverhair took a hesitant step forward. She dipped one foot in the water, and steeled herself to go farther.

Silverhair had an abiding dread of deep water. As a small calf, she had almost fallen into a fast-flowing glacier runoff stream. She had been washed down the stream, bobbing like a piece of rotten wood, her squeals all but drowned out by the rush of water. Only the fast brain and strong trunk of Wolfnose had saved her from being dashed against the rocks, or drowned.

Lop-ear waded clumsily back toward her; he splashed her, and the water droplets were icy. "I’m sorry," he said. "I forgot. That was stupid of me."

"It’s all right. I’m just being foolish."

Lop-ear grunted. "There’s nothing foolish about learning to avoid danger." He quoted the Cycle: "The wolf’s first bite is its responsibility. Its second is yours. I’m being selfish—"

"No." And Silverhair waded forward deliberately, leading the way into the ocean.

The water immediately soaked through the hair over her legs. Close to freezing, its cold penetrated to her skin. Her hair, waving like seaweed around her belly, impeded her progress. The sheets of land-fast ice crackled around her legs and chest.

Lop-ear stopped her. "That’s far enough," he said. "Now…"

Awkwardly he kneeled down so his chest was immersed. Then he dipped his head; soon the water was lapping over his eyes and forehead.

He lifted his head in a great spray, and she could see frost forming on his hair and eyelashes. He said, "Did you hear me?"

With great reluctance, she dropped her head so that her trunk and right ear were immersed in the icy water. Lop-ear extended his trunk underwater and emitted a series of strange calls: deep-toned whistles and bleats mixed with higher-pitched squeaks and squeals.

"What are you doing?"

"Calling our Cousins. The Calves of Siros. Don’t you know your Cycle? The sea cows, Silverhair."