As they started up into the rugged hills, they found themselves having to backtrack and work their way around deep holes and broken formations that blocked their way. Ayla thought the land seemed more barren, though with the deepening cold she wondered if it might be the changing season that gave that impression. Looking back from the heightened elevation, they gained a new perspective of the land they had crossed. The few deciduous trees and brush were bare of leaves, but the central plain was covered with the dusty gold of dry standing hay that would feed multitudes through the winter.
They sighted many large grazing animals, in herds and individually. Horses seemed most prevalent to Ayla, perhaps because she was especially conscious of them, but giant deer, red deer, and, particularly as they reached the northern steppes, reindeer were also abundant. The bison were gathering into large migratory herds and heading south. During one whole day, the great humpy beasts with huge black horns moved over the rolling hills of the northern grassland in a thick, undulating carpet, and Ayla and Jondalar stopped often to watch. The dust rose to cast an obscuring pall over the great moving mass, the earth shook with the pounding hooves of their passage, and the combined roar of the multitude of deep rolling grunts and bawls growled like thunder.
They saw mammoths less often, usually traveling north, but even from a distance the giant woolly beasts commanded attention. When not driven by the demands of reproduction, male mammoths tended to form small herds with loose ties for companionship. Occasionally one would join a female herd and travel with it for a while, but whenever the Journeyers noticed a lone mammoth, it was invariably male. The larger permanent herds were of closely related females; a grandmother, the old and wily matriarch who was their leader, and sometimes a sister or two, with their daughters and grandchildren. The female herds were easy to identify because their tusks tended to be somewhat smaller and less curved, and there were always young ones with them.
Though also impressive when they were sighted, woolly rhinoceroses were most rare and least social. They didn't, as a rule, herd together. Females kept to small family groups and, except during mating, males were solitary. Neither mammoths nor rhinoceroses, except for the young and the very old, had much to fear from four-legged hunters, not even the huge cave lion. The males in particular could afford to be solitary; the females needed the herds to help protect their young.
The smaller woolly musk-oxen, however, who were goatlike creatures, all banded together for protection. When they were under attack, the adults usually packed themselves into a circular phalanx facing outward, with the young ones in the middle. A few chamois and ibex made an appearance as Ayla and Jondalar climbed higher in the hills; they often dropped down to lower ground with the approach of winter.
Many of the small animals were secure for the winter in their nests burrowed deep in the ground, surrounded by stores of seeds, nuts, bulbs, roots, and, in the case of pikas, piles of hay that they had cut and dried. The rabbits and hares were changing color, not to white, but to a lighter mottled shade, and on a wooded knoll they saw a beaver and a tree squirrel. Jondalar used his spear-thrower to get the beaver. Besides the meat, the fatty beaver tail was a rare and rich delicacy, roasted by itself on a spit over the fireplace.
They usually used the spear-throwers for the larger game they hunted. They were both quite accurate with the weapons, but Jondalar had more power, could throw farther. Ayla often brought down the smaller animals with her sling.
Though they didn't hunt them, they noticed that otter, badger, polecat, marten, and mink were also numerous. The carnivores – foxes, wolves, lynxes, and larger cats – found sustenance in small game or the other herbivores. And though they seldom fished on this leg of their Journey, Jondalar knew there were sizable fish in the river, including perch, pike, and very big carp.
Toward evening they saw a cave with a large opening and decided to investigate it. As they approached, the horses did not show any nervousness, which the humans took to be a good sign. Wolf sniffed around with interest when they entered the cave, obviously curious, but no hackles were raised. Seeing the unconcerned behavior of the animals, Ayla felt confident that the cave was empty, and they decided to camp for the night.
After building a fire, they made a torch to explore a little deeper. Near the front were many signs that the cave had been used before. Jondalar thought the scrapes on the walls were either from a bear or a cave lion. Wolf smelled out droppings nearby but they were so dry and old that it was hard to tell what animal had made them. They found large, dry leg bones that had been partly eaten. The way they were broken and the teeth marks made Ayla think cave hyenas had cracked them with their extremely powerful jaws. She shuddered with repugnance at the thought.
Hyenas were no worse an animal than any other. They scavenged the carcasses that had died naturally and the kills of others, but so did other predators, including wolves, lions, and humans, and hyenas were also effective pack hunters. That didn't matter, Ayla's hatred of them was irrational. To her they represented the worst of all that was bad.
But the cave had not been used recently. All the signs were old, including the charcoal in a shallow pit from the fire of some other human visitor. Ayla and Jondalar went into the cave for some distance, but it seemed to go on forever, and beyond the dry front opening there were no signs of use. Stone columns, seeming to grow up from the floor or down from the ceiling and sometimes meeting in the middle, were the only inhabitants of the cool damp interior.
When they came to a bend, they thought they heard running water from deep within, and they decided to turn back. They knew the makeshift torch would not last long, and neither of them wanted to go beyond sight of the fading light from the entrance. They walked back touching the limestone walls and were glad to see the drab gold of dry grass and brilliant golden light outlining clouds in the west.
As they rode deeper into the highlands north of the great central plain, Ayla and Jondalar noticed more changes. The terrain was becoming pocked with caves, caverns, and sinkholes that ranged from bowl-shaped dips covered with grass, to inaccessible drop-offs that fell to great depths. It was a peculiar landscape that made them feel vaguely uneasy. While surface streams and lakes were rare, they sometimes heard the eerie sound of rivers running underground.
Unknown creatures of warm ancient seas were the cause of that strange and unpredictable land. Over untold millennia, the sea floors grew thick with their settling shells and skeletons. After even longer eons, the sediment of calcium hardened, was lifted high by conflicting movements of the earth, and became rocks of calcium carbonate, limestone. Underlying great stretches of land, most of the earth's caves were formed out of limestone because, given the right conditions, the hard sedimentary rock will dissolve.
In pure water, it is hardly soluble at all, but water that is even slightly acid attacks limestone. During warmer seasons and when climates were humid, circulating ground water, bearing carbonic acid from plants and charged with carbon dioxide, dissolved vast quantities of the carbonate rock.
Flowing along flat bedding planes and down minute cracks at the vertical joints in the thick layers of the calcareous stone, the ground water gradually widened and deepened the fissures. It carved jagged pavements and intricate grooves as it carried the dissolved limestone away, to escape in seepages and springs. Forced to lower levels by gravity, the acidic water enlarged underground cracks into caves. Caves became caverns and stream channels, with narrow vertical shafts opening into them, and eventually joined with others to become entire subterranean water systems.