Seeing what happened next.

When she had got her breath back she rolled to all fours and scuttled into the shade of the tree that had broken her fall.

Remembrance’s time might have been called the Age of the Atlantic.

Since the fall of man the continents’ chthonic dance had continued. That great ocean, born as a crack in Pangaea over two hundred million years ago, was continuing to widen as new seabed erupted endlessly along the line of the midocean ridge. The Americas had drifted westward, and South America had broken away from North to resume its interrupted career as an island continent. Meanwhile the cluster of continents around Asia had drifted east, so that the Pacific was slowly closing up. Alaska had reached out to Asia, rebuilding the Bering Strait bridge that had been made and undone repeatedly by the Ice Age glaciations.

There had been tremendous, protracted collisions. Australia had migrated north until it rammed itself into southern Asia, and Africa had crashed into southern Europe. It was as if the continents were crowding into the northern hemisphere, leaving the south abandoned save for lonely, icebound Antarctica. But Africa itself had fragmented, as the mighty wound of the ancient Rift Valley had deepened.

Where continents met, new mountain ranges were stitched. Where the Mediterranean had been there was now a mighty mountain range that reached eastward toward the Himalayas. It was the final extinction of the ancient Tethys. No trace of Rome had survived: the bones of emperors and philosophers alike had been crushed, melted, and gone swimming into the Earth itself. But while mountains were built, others evaporated like dew. The Himalayas were eroded to stumps, opening up new migration routes between India and Asia.

Nothing mankind had done in its short and bloody history had made the slightest bit of difference to this patient geographical realignment.

Meanwhile the Earth, left to its own devices, had deployed a variety of healing mechanisms, physical, chemical, biological, and geological, to recover from the devastating interventions of its human inhabitants. Air pollutants had been broken up by sunlight and dispersed. Bog ore had absorbed much metallic waste. Vegetation had recolonized abandoned landscapes, roots breaking up concrete and asphalt, overgrowing ditches and canals. Erosion by wind and water had caused the final collapse of the last structures, washing it all into sand.

Meanwhile the relentless processes of variation and selection had worked to fill an emptied world.

The sun climbed higher. Despite all that had happened to Remembrance, it was not yet midday.

She was stranded on a grassy plain, with purple volcanic hills in the distance, a few sparse stands of trees and shrubs, and a brown patch of borametz, the new kind of tree. Here, in the rain shadow of those purple hills, the rainfall was intermittent and erratic. The soil was habitually dry, and in such conditions trees were unable to establish themselves, and the grasses continued their ancient dominion — almost. Even vegetable communities evolved. And now the grasses had new competitors, in the borametz groves.

The tree that had saved her from the fall was barren of fruit, parched, clinging to life in the dry soil of this grassland. There was nothing to eat here — nothing but the scorpions and beetles that squirmed from beneath the rocks, bugs she popped into her mouth.

She made out a belt of forest, huddled against those remote purple hills, shimmering in the heat haze. Vaguely she realized that if she could get there she would be safer, she might find food, even people of her own kind.

But the forest was far away. Remembrance’s distant grandmothers would have easily walked across this stretch of open savannah. But not Remembrance. She was too clumsy a walker. And like Capo, a chimplike ape of a different time, her kind had regrown their hair and forgotten how to sweat.

So she sat there, her mind empty of plans, waiting for something to turn up.

Suddenly a slim head swooped down from the washed-out sky. Remembrance chattered and flinched back against the tree trunk. She saw black round eyes, wide with surprise, set in a slender, fur-covered face, and two long ears that swept back against an elegant neck. It was a rabbit’s head — but it was large, as large as a gazelle’s.

The rabbit-gazelle evidently decided that the cowering hominid was no particular threat to her. She proceeded to crop at the grass that grew thinly in the shade of the tree.

Cautiously Remembrance crept forward.

Her visitor was one of a herd, she saw now, scattered over the plain and grazing patiently on the grass. They were tall, some twice as tall as she was. Slim, graceful, they looked like gazelles — but they were indeed descended from rabbits, as their long ears and small white tails clearly demonstrated.

The legs of these animals were like gazelles’, too. Their forelegs were straight, and could be locked into position to support the animal with little effort. But halfway down their hind legs these rabbits had backward-bending joints that were in fact ankles. The lower leg was like an extended foot — balanced on two hooflike toes — and the knee was up near the torso, hidden in fur. Their back legs held in a permanent sprinter’s crouch, the rabbit-gazelles were constantly ready for flight, the most critical task in their lives. As they grazed, the youngest scuttling at the feet of their elders, the herd remained compact, and there was never a time when at least one of the adults was not scanning the grass.

The reason for all of this soon became apparent. One of the bigger bucks startled, went rigid, fled. The rest of the herd followed immediately, in a blur of speed and dust.

From the cover of a bluff of rocks a slim black form darted forward. It was another rat, this one shaped to run with the low-slung power of a cheetah. The rat-cheetah disappeared into the dust, pursuing the rabbit herd.

Stillness resumed. For a time, nothing moved over the grass-covered plain, nothing but the shimmer of the air. The sun slid away from its height. But the heat did not lessen, and thirst clawed at Remembrance’s throat.

She crept out of her hiding place. Her very human face, with straight nose, small mouth and chin, wrinkled in the bright afternoon light. She raised herself to her full height and sniffed. She heard a lowing, a clattering of tusks that sounded as if it were coming from the east, away from the sun. And she smelled the tang of water.

She began to run that way. She moved in scurries, hurrying from one patch of covering shade to the next, with frequent drops to an all-fours lope. This daughter of mankind ran like a chimp.

At last she crested a shallow bluff of eroded sandstone. She found herself facing a broad lake. It was fed by streams that snaked from more distant hills, but she could see that it was choked with reeds and fringed by a broad mud pan. She found an acacia to shelter under, and peered out, trying to find a way to get to the water.

Here, just as they always had, the herbivores had gathered to drink.

She saw more rabbits. There were skittish gazellelike creatures of the kind she had seen before. But there were also heavier-built, bisonlike powerhouses — and, running around their feet, smaller creatures that hopped and jumped. The rabbits, widespread and fast breeding, had, after the fall of man, radiated and adapted quickly. But not all of the new species had abandoned the ancient ways. There were still smaller browsers, especially in the forests where small beasts kicked and leapt and hopped as their ancestors always had.

Meanwhile warthogs snuffled and snorted in the muddy fringe of the lake, left all but unchanged by time. If there was no need to adapt, nature was conservative. And Remembrance made out huge, slow-moving creatures, marching serenely through the shallow water. They were related to the goats she had encountered in the forest, but these were giants, with tree trunk legs and horns that curled like mammoth tusks. They lacked trunks — none of these ruminants had evolved that particular anatomical trick — but, giraffelike, they had long necks that let them reach the succulent leaves growing on low-hanging tree branches, or the water of the lake.