As they toiled away into the thickening gray murk, Icebones realized that the grandmother was not following.

She turned back. To find her way she had to probe with her trunk through the murk. The smoke and ash were so thick now it was hard to breathe.

The grandmother had slumped to her knees, and her belly was flat on the ground, guard hairs trailing around her. Her eyes were closed, her trunk coiled limply before her, and her breath was a shallow labored scratch.

"You must get up. Come on." Icebones nudged the old one’s rump with her forehead, trying to force her to stand. She trumpeted to the others, "Help her!"

The grandmother’s rumble was weak, deep, almost inaudible over the shuddering of the rocky ground. "Let them go." She slumped again, her breath bubbling, her body turning into a shapeless gray mound under the ash.

Icebones feverishly probed at the old one’s face and mouth with her trunk. "I will see you in the aurora."

One eye opened, like a stone embedded in broken flesh and scorched hair. "There is no aurora in this place, child."

Icebones was shocked. "Then where do we go when we die?"

The old one closed her eyes. "I suppose I’ll soon find out." Her chest was heaving as she strained at the hot, filthy air. She raised her trunk, limply, and pushed at Icebones’s face. "Go. Your mother would be proud of you."

Icebones backed away. She was immersed in strangeness and peril, far from her Family — and now she was confronted by death. "I will Remember you."

But the grandmother, subsiding as if into sleep, did not seem to hear, and Icebones turned away.

It was the greatest volcano in the solar system. It had been dormant for tens of millions of years. Now it was active once more, and its voice could be heard all around this small world.

And, across the volcano’s mighty flanks, the small band of mammoths toiled through fire and ash, seeking shelter.

The blazing rocks continued to fall from the sky, splashing against the stolid ground.

The rocky tube shuddered and groaned. Sometimes dust or larger fragments of the inner roof came loose, and the mammoths, huddled together, squealed in terror. But the tube held, protecting them.

The darkness of night closed in. Still the ash snow fell thickly. The cave grew black. The mammoths tried to ignore the hunger and thirst that gnawed at them all.

Sometimes, in the darkness, Icebones heard the others snore or mumble. Icebones felt weariness weigh on her too. But she was reluctant to fall back into the dark, having emerged from that timeless, dreamless Sleep so recently.

She felt compassion for these wretched nameless ones — but at the same time her own fear deepened, for it was apparent that there was nobody here who could help her, no Family or Matriarch or even an experienced, battle-scarred old Bull.

She wished with all her heart that Silverhair was here.

The morning came at last, bringing a thin pinkish light that only slowly dispelled the purple-black of night. But the ash continued to fall, and there was a renewed round of rock falls.

The mammoths were forced to stay cooped up together in the lava tube, bickering and trying to avoid each other’s dung, which was thin and stinking of malnourishment.

By mid-afternoon, thirst drove them out. They had to push their way through ash which had piled up against the mouth of their long cave.

The world had turned gray.

A cloud of thick noxious gas continued to pump out of the summit of this immense Fire Mountain, and a gray-black lid of it hung beneath the pink sky, darkening the day. Ash drifted down, turning the rocky ground into a field of gray smoothness over which the mammoths toiled like fat brown ghosts, every footfall leaving a crater in fine gray layers.

Everything moved slowly here, Icebones observed. As she walked her steps felt light, as if in a dream, or as if she was wading through some deep pond. When she kicked up ash flakes they fell back with an eerie calmness. Even the guard hairs of the mammoths rippled languidly.

Trying to ignore the strangeness, Icebones walked with exaggerated caution. If she must be called a Matriarch, she should fulfill the role. "The ash hides the rock’s folds and crevices," she said. "You must be careful not to injure yourselves." She showed the others how to probe at the ground ahead with their trunks, feeling out hidden traps.

But the Ragged One stalked alongside her, her posture stiff and mocking. "So you know all about ash. You know better than I do, after I have spent my whole life here on this Fire Mountain."

"No," said Icebones evenly. "But I have seen how snow covers the ground. And the dangers are surely alike."

The Ragged One growled. "There," she said. "There are dangers in this place you have never imagined."

Icebones saw that a new river was making its way down the broad flank of the Mountain. It was a river of fire.

Glowing red, it flowed stickily and slowly, like blood. It was crusted over by a dark brown scum that continually crumbled, broke and congealed again. Flames licked all along the length of the flow, and wispy yellow smoke coiled. In one place the flow cut through a frozen pond, and a vast cloud of yellow-white steam rose with a harsh hissing.

Icebones could smell the burning stench of the molten rock river, feel its huge rumble as it churned its way down the slope, cutting through layers of ancient rock as if they were no more substantial than ice. "We were fortunate," she said softly. "If that rock river had chosen to flow a little more to the east—"

"It would have overwhelmed our lava tube," said the Ragged One. "Yes. We would have been scorched, or buried alive, or crushed…"

"It is a shame the rock flow is destroying the pool. We could have drunk there."

The Raged One snorted. "In your wisdom you will find us more water."

Icebones, irritated, walked up the rocky slope. "Very well. Let’s find water."

Reluctantly the Ragged One followed.

Icebones came to an area where the ash was a little less thick. She walked back and forth across the rock, stamping, scraping exposed outcrops with her tusks and slapping them with her trunk, listening hard.

The young Bull approached, ungainly on his oddly elongated legs. "What are you doing?"

Feeling like a foolish infant — she had to remind herself that this towering Bull was only a calf himself — she said, "I’m looking for water."

"There is no water here."

"Yes, there is. But it’s deep underground. Can’t you hear it?"

Comically, he cocked his small ears. "No," he said.

"Listen with your belly and feet and chest." She stamped again. "The ground here is hard and it rings well. And the water that flows deep makes the rock shudder…" To Icebones, the rumble of the deep water was a distinct noise under the frothy din of the surface world, like the far-off call of a thunderstorm, or the giant crack of a distant glacier calving an iceberg.

The Bull raised his trunk, as if to smell the deep-buried water. He rammed his tusks against the hard, rippled rock, but they rebounded, and he yelped with pain.

"We must find a place where the water comes closer to the surface." She walked down the hillside, pausing to stamp and listen, tracking the path of the underground river.

The others followed, the Bull with eagerness, the rest with incomprehension or resentment, but all driven by their thirst.

She came to a place where a vast pipe thrust out of the ground. It stalked away over the rocky slope on spindly legs, like some immense centipede. The pipe was as wide as three or four mammoths standing side by side, and its surface was slick and white, like a tusk.

The pipe was obviously a creation of the Lost. But its purpose did not interest her — for she could hear water running through it.