With Bobby’s unspoken consent, David released the moment, and they fell away once more. The background blurred into a blue-green wash, and the ancestor’s face flowed, growing smaller, her eyes wider and habitually black. Perhaps she had become nocturnal.
Bobby glimpsed vegetation, thick and green, much of it unfamiliar. And yet now the land seemed strangely empty: no giant herbivores, no pursuing carnivores crossed the empty stage beyond his ancestor’s thin-cheeked, shadowed, huge-eyed face. The world was like a city deserted by humans, he thought, with the tiny creatures, the rats and mice and voles burrowing among the huge ruins.
But now the forests began to shrink back, melting away like summer mist. Soon the land became skeletal, a plain marked by broken stumps of trees that must once have risen tall.
Ice gathered suddenly, to lie in thick swaths across the land. Bobby sensed life drawing out of this world like a slow tide.
And then clouds came, immersing the world in darkness. Rain, dimly glimpsed, began to leap from the darkened ground. Great heaps of bones assembled from the mud, and flesh gathered over them in gray lumps.
‘Acid rain,’ murmured David.
Light flared, dazzling, overwhelming.
It was not the light of day, but of a fire that seemed to span the landscape. The fire’s violence was huge, startling, terrifying.
But it drew back.
Under a leaden sky, the fires began to collapse into isolated blazes that dwindled further, each licking flame restoring the greenery of another leafy branch. The fire drew at last into tight, glowing pellets that leapt into the sky, and the fleeing sparks merged into a cloud of shooting stars under a black sky.
Now the thick black clouds drew back like a curtain. A great wind passed, restoring smashed branches to the trees, gently ushering flocks of flying creatures to the branches. And on the horizon a fan of light was gathering, growing pink and white, at last turning into a beacon beam of brilliance pointing directly up into the sky.
It was a column of molten rock.
The column collapsed into an orange glow. And, like a second dawn, a glowing, diffuse mass rose above the horizon, a long, glowing tail spreading across half the sky in a great flamboyant curve. Masked by the daylight, brilliant in the night, the comet receded, day by day, drawing its cargo of destruction back into the depths of the Solar System.
The brothers paused in a suddenly restored world, a world of richness and peace.
The ancestor was a wide-eyed, frightened creature that lingered above ground, perhaps incautiously trapped there.
Beyond her, Bobby glimpsed what appeared to be the shore of an inland sea. Lush jungles lapped the swampy lowlands along the coast, and a broad river decanted from distant blue mountains. The broad ridged backs of what must be crocodiles sliced through the river’s sluggish, muddy waters. This was a land thick with life- unfamiliar in detail, and yet not so unlike the forests of his own youth.
But the sky was not a true blue-more a subtle violet, he thought; even the shapes of the clouds, scattered overhead, seemed wrong. Perhaps the very air was different here, so deep in time.
A herd of homed creatures moved along the swampy coast, looking something like rhinos. But their movements were strange, almost birdlike, as, lumbering, they mingled, browsed, nested, fought, preened. And there was a herd of what looked at first glance like ostriches- walking upright, with bobbing heads, nervous movements and startled, suspicious glances.
In the trees Bobby glimpsed a huge shadow, moving slowly, as if tracking the giant plant-eaters. Perhaps this was a carnivore-even, he thought with a thrill, a raptor.
All around the dinosaur herds, clouds of insects hovered.
‘We’re privileged,’ David said. ‘We’ve a relatively good view of the wildlife. The dinosaur age has been a disappointment for the time tourists. Like Africa, it turns out to be huge and baffling and dusty and mostly empty. It stretches, after all. over hundreds of millions of years.’
‘But,’ Bobby said dryly, ‘it was kind of disappointing to discover that T. rex was after all just a scavenger … All this beauty, David, and no mind to appreciate it. Was it waiting for us all this time?’
‘Ah, yes, the unseen beauty. ‘Were the beautiful volute and cone shells of the Eocene epoch and the gracefully sculpted ammonites of the Secondary period created that man might ages afterward admire them in his cabinet?’ Darwin, in the Origin of Species.’
‘So he didn’t know either.’
‘I suppose not. This is an ancient place, Bobby- You can see it: an antique community that has evolved together, across hundreds of millions of years. And yet.’
‘And yet it would all disappear, when the Cretaceous Wormwood did its damage.’
‘The Earth is nothing but a vast graveyard, Bobby. And, as we dive deeper into the past, those bones are rising again to confront us … .’
‘Not quite. We have the birds.’
‘The birds, yes. Rather a beautiful end to this particular evolutionary subplot, don’t you think? Let’s hope we turn out so well. Let’s go on.’
‘Yes.’
So they plunged once more, dropping safely through the dinosaurs’ Mesozoic summer, two hundred million years deep.
Ancient jungles swept in a meaningless green wash across Bobby’s view, framing ‘the timid, mindless eyes of millions of generations of ancestors, breeding, hoping, dying.
The greenery abruptly cleared, revealing a flat dusty plain, an empty sky.
The denuded land was a desert, baked hard and flat beneath a high, harsh sun, the sands uniformly reddish in color. Even the hills had shifted and flowed, so deep was time.
The ancestor here was a small reptile-like creature who nibbled busily on what looked like the remains of a baby rat. She was on the fringe of a scrubby forest, of stunted ferns and conifers, that bordered a straggling river.
Something like an iguana scampered nearby, flashing rows of sharp teeth. Perhaps that was the mother of all the dinosaurs, Bobby mused. And, beyond the trees,
Bobby made out what looked like warthogs, grubbing in the mud close to the sluggish water.
David grunted. ‘Lystrosaurs’ he said. ‘Luckiest creatures who ever lived. The only large animal to survive the extinction event.’
Bobby was confused. ‘You mean the dinosaur-killer comet?’
‘No,’ David said grimly. ‘I mean another, the one we must soon pass through, two hundred and fifty million years deep. The worst of them all … ‘
So that was why the great lush jungle panorama of the dinosaurs had drawn back. Once again, the Earth was emptying itself of life. Bobby felt a profound sense of dread.
They descended once more.
At last the final, stunted trees shuddered back into their buried seeds, and the last greenery-struggling weeds and shrubs-shriveled and died. A scorched land began to reconstitute itself, a place of burned-out stumps and fallen branches and, here and there, heaped-up bones. The rocks, increasingly exposed by the receding tide of life, became powerfully red.
‘It’s like Mars.’
‘And for the same reason,’ David said grimly. ‘Mars has no life to speak of; and, in life’s absence, its sediments have rusted: slowly burning, subject to erosion and wind, killing heat and cold. And so Earth, as we approach this greatest of the deaths, was the same: all but lifeless, the rocks eroding away.’
And all through this, a chain of tiny ancestors clung to life, subsisting in muddy hollows at the fringes of inland seas that had almost-but not quite-dried to bowls of lethal Martian dust.
Earth in this era was very different, David said. Tectonic drift had brought all of the continents into a single giant assemblage, the largest landmass in the history of the planet. The tropical areas were dominated by immense deserts, white the high latitudes were scoured by glaciation. In the continental interior the climate swung wildly between killing heat and dry freezing.
And this already fragile world was hit by a further calamity; a great excess of carbon dioxide, which choked animals and added greenhouse heating to an already near-lethal climate.
‘Animal life in particular suffered: almost knocked back to the level of pond life. But for us it’s nearly over, Bobby; the excess CO, is drawing back into where it came from: deep sea traps and a great outpouring of flood basalts in Siberia, gases brought up from Earth’s interior to poison its surface. And soon that monstrous world continent will break up.
‘Just remember this: life survived. In fact, our ancestors survived. Fix on that. If not, we wouldn’t be here.’ As Bobby studied the flickering mix of reptile and rodent features that centered in his vision, he found that idea cold comfort They moved beyond the extinction pulse into the deeper past.
The recovering Earth seemed a very different place. There was no sign of mountains, and the ancestors clung to life at the margins of enormous, shallow inland seas that washed back and forth with the ages. And, slowly, after millions of years, as the choking gases drew back into the ground, green returned to planet Earth.