The mesonychid was a kind of condylarth, a diverse group of animals related to the ancestors of hoofed animals. The meso was not an expert killer or a meat specialist but, like a bear or wolverine, it was an opportunistic feeder. All the condylarths were doomed to extinction ten million years before the age of mankind. But for now they were in their pomp, top predators of the world forest.
The other inhabitants of the forest floor reacted in their different ways. The lorislike adapid had a shield of thickened skin over bony bumps on its back, beneath which it now tucked its head. The big, dull barylambda concluded it was under no threat even from a pack of these small hunters; like the hyenas of later ages, the mesos were primarily scavengers and rarely attacked an animal much bigger than themselves. The taeniodont, however, decided that caution was called for; pompously it trotted away, its gaping mouth showing its high teeth.
Meanwhile the plesi fought on, inflicting scratches and bites on its assailants. One of the mesos was left whining, the tendons of its right hind leg badly ripped, blood leaking from torn flesh. But at last the plesi succumbed to their teeth and weight. The mesos formed a loose circle around their victim, their slim bodies and waving tails clustered around their meal like maggots around a wound. The rising stink of blood, and the fouler stench of panic shit and stomach contents, overwhelmed Noth’s sensitive nose.
Though some of the ancient plesiadapids had specialized, learning how to husk fruit like opossums or to live off the gum of trees, they remained primarily insect eaters. But now they faced competition from other insectivores, the ancestors of hedgehogs and shrews — and from their own descendant forms like the notharctus. Already the early-form plesis had become extinct across much of North America, surviving only in fringe areas like this marginally habitable polar forest, where the endless days did not suit bodies and habits shaped during the nights of the Cretaceous. Soon the last of them would be gone.
Noth, high in the cathedral calm of the trees, could see the family as they climbed up toward him, their lithe limbs working smoothly. But something disturbed him: a shift in the light, a sudden coldness. As clouds crowded past the sun, the great forest-spanning buttresses of light were dissolving. Noth felt cold, and his fur bristled. Rain began to fall: heavy misshapen drops that clattered against the trees’ broad leaves and pounded like artillery shells into the mud below.
It was because of the onset of the rain, and the overwhelming stink of the bloody deaths below, that Noth did not detect the approach of Solo.
Hidden in a patch of shadow, his scent blowing downwind, Solo saw the notharctus troop scurrying to safety.
And he saw Noth’s mother with her infant.
She was a fertile, healthy female: that was what the presence of the infant told him about her. But there was a mate with her, and since she already had a pup, she was unlikely to come into heat again this season. Neither of those factors were an obstacle to Solo. He waited until Noth’s family had settled on a branch, calming down, out of immediate danger.
Solo, at three years old, was a mature, powerful male notharctus. And he was something of a freak.
Most males roamed the forests in small bands, seeking out the larger, more sedentary troops of females where they might find a chance to mate. Not Solo. Solo preferred to travel alone. He was larger and more powerful than almost all the females he had encountered in his travels in this polar forest. Again, in this Solo was unusual; the average adult male was smaller than the average female.
And he had learned to use his strength to get what he wanted.
With a lithe swing Solo dropped down to the branch and stood upright before Noth’s mother. He looked unbalanced, for his hind legs were comparatively massive, his forearms short and slender, and he held his long tail up in the air so that it hooked over his head. But he was tall, and very still, and very intimidating.
Noth’s mother could smell this huge stranger:
Noth’s father came forward. He raised himself up on his hind legs and faced the intruder. Moving with fast jerky gestures he rubbed his genital glands against the foliage around him, and swept his tail over his forearms so that the horny spurs above his wrist glands combed through his tail fur and impregnated it with his scent. Then he waved the lustily stinking tail above his head at the intruder. In the scent-dominated world of the notharctus, it was an awesome display.
There was nothing sentimental in the father’s behavior. Producing healthy offspring that survived to breeding age was the only purpose of this father’s life; he was preparing to take on the intruder solely through a selfish drive to see his own heritage preserved.
Usually this game of malodorous bluff would have continued until one or the other of the males backed down, without physical contact. But again Solo was unusual. He did not respond with any form of display, save for a cold stare at the other’s feverish posturing.
Noth’s father was unnerved by the newcomer’s eerie stillness. He faltered, his scent glands drying, his tail drooping.
Then Solo struck.
With teeth bared he lunged at Noth’s father, slamming into his chest. Noth’s father fell back, squealing. Solo dropped to all fours and fell on him, biting into his chest through a layer of fur. Noth’s father screamed and scurried out of sight. He was only slightly injured, but his spirit was broken.
Now Solo turned on the females. The aunts could easily have resisted Solo, if they had combined their efforts. But they scrambled out of Solo’s way. Solo’s assault had disturbed them as much as its victim. They had never seen anything like it. All of them were mothers; all thought immediately of the infants they had left parked in the high branches.
Solo ignored them too. With a carnivore’s steely movements he advanced on Noth’s mother, his principal target.
She hissed, she showed her teeth, she even kicked at him with her powerful hind legs. But he resisted her blows easily, walked through her kicking — and took the unresisting, baffled infant from her grasp. He bit quickly into the pup’s throat, opening up the flesh, and rummaged there until he had ripped open the infant’s trachea. It was over in heartbeats. He dropped the quivering scrap into the forest below, where mesonychids, alerted by the scent of fresh blood, ran forward with their eerie uncaninelike barking. His mouth and hands bloodied, Solo turned to Noth’s mother. Of course she would not be fertile yet, perhaps not for some weeks, but he could mark her with his scent, make her his own, and repel the attentions of other males.
There was nothing truly cruel in Solo. If her pups were killed, it was possible Noth’s mother would come into heat again before the end of the summer — and if Solo covered her then, he could generate more offspring through her. So, for Solo, infanticide was a good tactic.
Solo’s brutal strategy wouldn’t have been sustainable for everybody. Notharctus males were not equipped to fight. They lacked the canine teeth that later primate species would use to inflict damage on rivals. And this polar forest was a marginal environment where true fights were literally a waste of energy, a squandering of scarce resources, which was why the ritual stink fights had evolved. But for Solo, the exception, it was a strategy that worked, over and over, and which had won him many mates — and which had generated many offspring, scattered through the forest, whose veins ran with Solo’s blood.
But it wasn’t going to work this time.
Noth’s mother, marked by the killer’s scent, gazed down into the green void below. She had lost her baby — just as Purga, her remote grandmother, had once endured. But, considerably more intelligent than Purga had been, she was much more acutely aware of her pain.
Blackness filled her. She lunged at Solo, her small limbs flailing, mouth gaping. Startled, he darted back.
She lunged past him. And she fell.
Noth saw his mother fall into the pit where his infant sister had fallen before. Immediately her twisting form was lost under the slick, writhing bodies of the mesos.
Noth had been weaned a few weeks after he had been born. Soon would have come a time when he would have wandered from the troop. His link to his mother was tenuous. And yet he felt a loss as powerful as if his mother’s breast had been ripped from his mouth.
And still the rain fell, harder all the time.
Noth, shivering, crawled through the branches. With the wind low, the rain fell in massive drops that pounded exposed flesh and hammered against the trees’ broad leaves.
Following lingering traces of his mother’s scent, he found his baby sister. She still clung motionless to the tree trunk where her mother had parked her — where she would have clung, probably, until she starved. Noth sniffed her damp fur. He huddled up close and wrapped his arms around her. She was a tiny shivering mass against his belly fur, but he was sheltering her from the rain.
He was drawn to stay with her. She smelled of family; she shared much of his genetic inheritance, and therefore he had a stake in any offspring she might one day have.
But the rain fell through a night and a day, as the sun continued its purposeless dance around the sky. The forest floor became sodden, and glimmering pools, laden with floating leaf debris, began to cover the ground, hiding gnawed and scattered bones.
And the continuing rain washed away the last traces of the scent markers of Noth’s troop from the trees. Noth and his sister were lost.
II
As the endless day wore on, as the sun wheeled through its meaningless cycles, Noth and Right stumbled through the forest’s branches.
They had already been lost for a week. They had found none of their own kind. But here in the forest canopy there were many adapids, cousins of the notharctus. Many of them were smaller than Noth. He would glimpse their glowing eyes, like eerie yellow pits, peering out of a shadowed nook. These miniature insect hunters looked more like mice. Some of them scuttled along branches, racing from shaded cover to cover. But one made a spectacular upright leap from tree to tree, its powerful hind legs dangling, its paws reaching. Its membranous ears swiveling like a bat’s, it caught an insect, plucking it out of the air in its jaws in midjump.
One solitary little creature clung to the rotten bark of an ancient tree. It had a scruffy black coat, batlike ears, and prominent front teeth, and it tapped patiently at the wood with a claw-tipped finger, its large ears swiveling. When it heard a larva burrowing under the bark, it ripped off the bark with its teeth and plunged in a peculiarly long middle finger to hook the larva and deliver it to its gaping, greedy mouth. This was a primate that had learned to live like a bird, like a woodpecker.
Once Noth blundered into a giant, slothlike creature hanging upside down from a thick branch, its primate’s hands locked around the wood. This monster’s head swiveled to inspect Noth and Right, its eyes blank. Its mouth chewed slowly, crammed full of the fat deciduous leaves that were its principal diet. Its kind had been driven to larger sizes by the need to accommodate a gut big enough to break down the cellulose in the leaves’ cell walls. The sloth-thing’s face was oddly immobile, static, limited in its expressiveness. The social life of this gloomy hanging creature was unexciting; its slow metabolism, and lack of spare energy to devote to social activities, saw to that.
The world had warmed steadily since the terrible impact. Waves of vegetation had migrated away from the equator, until tropical rain forest eventually covered all of Africa and South America, North America to what would become the Canadian border, China, Europe as far north as France, and much of Australia. Even at the poles there were jungles.
North America was still joined by mighty land bridges to Europe and Asia, while the southern continents lay in a great band below the equator, like scattered islands. India and Africa were both migrating north, but for now the Tethys Sea still girdled the equator, a mighty current that spread warmth around the belly of the planet. The Tethys was like a river through Eden.
In response to the great warming, the children of Plesi and other mammals had at last thrown off their past. It was as if the Earth’s inheritors had finally realized that the empty planet offered them a lot more than just another kind of grub to chew. While the reptilian survivors, the lizards, crocodiles, and turtles, clung on largely unchanged, soon the foundations of the successful mammalian lineages of the future would be laid down.
Plesi, like Purga, had been a low-slung crawler, with the typical mammalian four-footed head-down body stance. But her primate descendants grew larger, with more powerful hind limbs to support upright bodies and heads. Meanwhile the primates’ eyes had moved forward to the front of their faces. This would give them three-dimensional vision, enabling them to judge their increasingly long leaps, and to triangulate on the prey insects and small reptiles that still formed part of their diet. And as they explored different ways to make a living, the primates would fan out into
