But there came a time when some Hotbloods did not return from the nightly foraging expeditions, just as it had been before. And then, one day, Kilukpuk was wakened from a dreamless sleep by a slam-slam-slam that shook dirt from the roofs of the burrows.

Aglu, her brother, came running through the burrows. "It is the Reptiles! They have returned!"

Kilukpuk gathered her calves to her. They were terrified and bewildered.

After that, things rapidly got worse. More foragers were lost on the surface. The Hotbloods became as fearful and hollow-eyed as they had ever been, and food soon began to run short in the burrows.

But Kilukpuk could not help but notice that not all the Hotbloods were suffering so. While the others were skinny and raddled by disease, Aglu and his band of companions seemed sleek and healthy. Kilukpuk grew suspicious, though her suspicion saddened her, for she still loved her brother deeply.

At last, one night, she followed Aglu and his companions to the surface. She saw that Aglu and the others made little effort to conceal themselves — in fact, they laughed and cavorted in the Moonlight.

Then they did a very strange thing.

When they had eaten their fill of the roots and green plants, Aglu and his friends climbed up low bushes and hurled themselves at the ground. They pushed pebbles off low outcrops and let them dash against the ground. They even picked up heavy branches and slammed them against the ground — all the time roaring and howling as if they were Reptiles themselves.

And when an unwary Hotblood came poking her nose out of the ground, Aglu and his friends prepared to attack her.

Immediately Kilukpuk rose up with a roar of rage. She fell on Aglu and his followers, cuffing and kicking and biting them, scattering their pebbles and their sticks.

The Hotblood whose life had been spared ran away. Aglu’s followers soon fled, leaving Kilukpuk facing her brother. She picked him up by the scruff of the neck. "So," she said, "you are the mighty Reptile that has terrified my calves."

"Let me go, Kilukpuk," he said, wriggling. "The Reptiles have gone. We are free—"

"Free to enslave your Cousins with fear? I should rip you to pieces myself."

Aglu grew frightened. "Spare me, Kilukpuk. I am your brother."

And Kilukpuk said, "I will spare you. For Hotblood should not kill Hotblood. But you are no brother of mine; and your mouth and fur stink of blood. Go now."

And she threw him as hard as she could; threw him so far, his body flew over the horizon, his cries diminishing.

She went back to the burrows to comfort her calves, and tell her people the danger was over: that they need not skulk in their burrows, that they could live on the land, not under it, and they could enjoy the light of the day, not cower in darkness.

And Kilukpuk led her people to the sunlit land, and they began to feed on the new plants that sprouted from the richness of the burned ground.

As for Aglu, some say he was ripped apart and eaten by his own calves, and they have never forgotten the taste of that grisly repast: for they became the bear and the wolf, and the other Hotbloods that eat their own kind.

Certainly Kilukpuk never gave up her vigilance, even as she grew strong and sleek, and her fertile loins poured forth generation after generation of calves. And her calves feared nobody.

Nobody, that is, except the Lost.

Silverhair, standing tall on the headland, was cupped in a land of flatness: a land of far horizons, a land of blue and gray, of fog and rain, of watery light no brighter than an English winter twilight.

It was the will of Kilukpuk, of course, that Silverhair should be the first to spot the Lost. Nobody but Silverhair — Silverhair the rebel, the Cow who behaved more like a musth Bull, as Owlheart would tell her — nobody but she would even have been standing here, alone, on this headland at the southwestern corner of the Island, looking out to sea with her trunk raised to test the air.

The dense Arctic silence was abruptly broken by the evocative calls of birds. Silverhair saw them on the cliff below her, prospecting for their colony: the first kittiwakes, arriving from the south. It was a sign of life, a sign of spring, and she felt her own spirits rise in response.

A few paces from Silverhair, in a hollow near the cliff edge, a solid bank of snow had gathered. Now a broad, claw-tipped paw broke its way out into the open air, and beady black eyes and nose protruded. It was a polar bear, a female. The bear climbed out, a mountain of yellow-white fur. She was lean after consuming her body fat over the winter, and her long, strong neck jutted forward; her muscles, long and flowing, worked as she glided over the crusted snow.

The bear saw Silverhair. She fixed the huge mammoth with a glare, quite fearless.

Then she stretched, circled, and clambered back in through the narrow hole to the cubs she had borne during the winter, leaving a hind leg waving in the air.

Amused, Silverhair looked to the south.

The black bulk of a spruce forest obscured her view of the coast itself — and of the mysterious Nest of Straight Lines that stood there, a place that could be glimpsed only when the air was clear of fog or mist or snow, a sinister place that no mammoth would willingly visit. But Silverhair could see beyond the forest, to the ocean itself.

Here and there, blown snow snaked across the landfast ice that fringed the Island’s coast. Two pairs of black guillemots, striking in their winter plumage, swam along the sea edge, mirrored in the calm water. Pack ice littered the Channel that lay between Island and Mainland. The ice had been smashed and broken by the wind; the glistening blue-white sheet was pocked by holes and leads exposing black, surging water.

Away from the shore the sea remained open, of course, as it did all year round, swept clear of ice by the powerful currents that surged there. Frost-smoke rose from the open water, turned to gold by the low sun. And beyond the Channel, twilight was gathering on that mysterious Mainland itself. It was the land from which — according to mammoth legend recorded in the Cycle — the great hero Longtusk had, long ago, evacuated his Family to save them from extinction.

And as the day waned she could see the strange gathering of lights, there on the Mainland: like stars, a crowded constellation, but these lights were orange and yellow and unwinking, and they clung to the ground like lichen. Silverhair growled and squinted, but her vision was poor. If only she could smell that remote place; if only it sent out deep contact rumbles rather than useless slivers of light.

And now heavy storm clouds descended on that unattainable land, obscuring the light.

In the icy breeze, the air crackled in her nostrils, and her breath froze in the fur that covered her face.

That was when she saw the Lost.

She didn’t know what she was seeing, of course.

All she saw was something adrift on the sea between Island and Mainland. At first she thought it was just an ice floe; perhaps the unmoving shapes on top of the floe were seals, resting as they chewed on their monotonous diet of fish and birds.

But she had never seen seals sitting up as these creatures did, never seen seals with fins as long and splayed as those — never heard voices floating over the water and the shore of ice and rock, as petulant and peevish as these.

Even the "ice floe" was strange, its sides and one end straight, the other end coming to a point like a tusk’s, its middle hollow, cupping the seal-like creatures inside. Whatever it was, it was drifting steadily closer to the Island; it would surely come to ground somewhere south of the spruce forest, and spill those squabbling creatures on the shore.