Evolution

None of the eggs had hatched. The euoplo, mournful, baffled on a deep cellular level, had moved away. Immediately after she was gone, a furry cloud of mammalian predators had descended on the eggs, in their squabbling reducing the nest to a muddy battlefield.

The last of her kind, the euoplo wandered the land, driven on by a final imperative: to survive. But the poison and the rain worked on her too. Creatures like Purga sheltered from the worst of the rain in her burrow, or under rocks — or even, once, under the scooped-out shell of a dead turtle. The euoplo was too big: There was nowhere for her to hide, and she could not burrow into the ground. So her back was ferociously scalded, and great bony plates of armor were stripped of flesh, the connecting ligaments etched and burned.

Unthinking, she staggered toward the sea.

Three months after the impact, Purga and Last stumbled across ground frozen as hard as rock.

They saw few animals: Sometimes a cautious frog would watch them go by, or a bird would flee at their approach, chirping with eerie loudness, abandoning some frozen bit of offal on the ground. The relics of the lush Cretaceous vegetation, the stumps of trees and patches of undergrowth, were now frozen as hard as blackened sculptures, and any attempt to gnaw them was rewarded only with a mouthful of ice, and more often than not a chipped tooth.

There were only two of them. Third had gone, lost to hypothermia.

Purga longed for security, to clamber into a tree or dig into the soft earth. But there were no trees — nothing but ash and stumps and bits of roots — and the ground was too hard to burrow into. When they needed to rest they could only grub in the looser debris, making loose nests of ash and burned leaves and bits of wood, where they would lie shivering, huddled to share body warmth.

After days of wandering, Purga and Last made their way slowly along the fringe of America’s inland ocean.

Even here the gritty beach was frozen, and the sea itself, as charcoal gray as the sky above it, was littered with ice floes. But the gentle swell still breathed salty water over the sand. And here at the fringe of the ocean the primates found food — seaweed, small crustaceans, even stranded fish.

The oceans, too, had been devastated by the impact. The loss of sunlight and the acid rain had massacred the photosynthetic plankton that had populated the ocean’s upper layers. With this key foundation of the ocean’s food chain gone, extinctions were following like tumbling dominoes. On wounded Earth, death stalked every realm, and the ice-littered waters of the darkened ocean hid a holocaust as horrific as that which was unfolding on the land. It would take a million years for the seas to recover.

Purga came across a stranded starfish. Still new to ocean foraging, she had never seen such a beast before. She poked it with her snout, trying to determine which of her world categories it most closely fit: a threat, or good to eat.

Her movements were listless. In fact she could barely see the starfish.

Purga was weakening. She was constantly thirsty, with a nagging pain that clung to her mouth and throat and sank deep into her belly. Since the impact she had lost weight steadily, from a scrap of a body that had little excess to start with. And she was a tropical creature suddenly stranded in arctic conditions. Though her layer of fur helped trap heat, her body form was long and lanky, lacking the spherical, enclosing shape of creatures adapted to the cold. So she burned up even more energy and body mass in shivering.

She was bony, enfeebled, continually exhausted, her thinking increasingly fuddled, her instincts dulled.

And she was getting old. Living as vermin, the primates’ principal survival tactic had been fast breeding: there had always been simply too many of them to be eliminated by the dinosaurs’ ferocious hunting. For such creatures, there was no premium on longevity. Already Purga was coming to the end of her short, explosive life.

Last suffered, too, of course. But, younger, she had more strength to spend. Purga was aware of a growing distance between them. It was not a question of disloyalty. This was the logic of survival. Purga sensed, deep down, that the day would come when her daughter would see her not as a foraging companion, not even as a hindrance, but as a resource. After all she had survived, maybe Purga’s final memories would be of her own daughter’s teeth at her throat.

But now they smelled meat. And they saw more survivors, more ratlike mammals, scurrying across the beach. There was something to be had. Purga and Last struggled to follow.

At last, her awareness flickering like a failing lightbulb, the great euoplo stumbled to the shore of the ocean.