This last thought came as I watched, virtually mesmerized, while a long, gleaming neck rose and rose and rose from the river until it blotted out the light. Vast sheets of water ran off its body and threatened to capsize the canoe as, with a shout to me to steady us, Ayanawatta took one of the spears from beneath his feet and threw it expertly into flesh I had assumed to be hugely dense. But the spear went deep into the creature, as if into a kind of heaving, wet sawdust, and the water bubbled with the thing's hissing breath. It groaned. I had not expected such a noise from it. The voice was almost human, baffled. It thrashed violently until the spear was flung free, and then it disappeared upstream, still groaning from time to time as its head broke the water, trailing a kind of thin, yellow ichor like smoke.

"I haven't seen anything close to that since I was in the Lower Devonian, " I said. I was still shaking. The word devour had gained a fresh resonance for me. "Did it mean to attack us?"

"It probably hoped to eat us, but those are known along this river as the Cowardly Serpents. It takes little to drive them off as you saw, although if they capsize your canoe, you are in some danger, of course."

Much as I was trained not to think in linearities I was aware that in this realm gigantic water-serpents had long since become extinct. I put this to Ayanawatta as he paddled to where his spear floated, shaft up, in the reedy, eddying water. A strong smell of firs and the noise of feeding birds came from the bank, and I drank in the simplicity of it to steady myself. I knew the supernatural better than that which my husband insisted on calling "natural, " but I felt resentful that I was being forced to take extra risks as I sought to save him. I said as much to Ayanawatta.

The Mohawk prince reassured me. He was simply obeying the demands of his dreamquest. This meant that my own dream-quest was in accordance with his, which meant that as long as we continued in the current pattern and made no serious mistakes our quests would be successful. We should both get what we desired. The wind was still blustering and slapping at our clothes. I drew my blanket closer. Ayanawatta hardly noticed the drop in temperature. As for the "prehistoric" nature of our dangers, he regretted that some sort of crisis had occurred. Such anomalies were becoming increasingly common. He believed that the source of our own troubles was also causing the disruptions. The great prairies offered natural grazing and ample prey for predators. They were, he admitted, generally moving south these days, and the altering climate took increasing numbers of those that remained.

I said that I had noticed it growing colder.

Still apparently oblivious of the chill, Ayanawatta sighed. "Once, " he said, "this was all unspoiled. Those serpents would never have come this far downriver. It means you lose all the river game, and before you know it the whole natural order is turned upside down. The consequences are disastrous. It becomes impossible to lead any kind of settled life. Do you see any villages on the banks these days? Of course not! It used to be wonderful here. Girls would wave at you. People would invite you in to hear your stories ..."

Grumbling thus, he paddled mechanically for a while. The encounter with the river serpent had not so much frightened as irritated him. Even I had not been terrified of the beast. But Ayanawatta's sense of order and protocol was upset, and he was becoming concerned, he said, about the wind.

Again he surprised me. He had a habit of noticing everything while appearing to be entirely concerned with his own words. For such people, words were sometimes a kind of barrier, the eye of a storm, from which part of them could observe the world without the world ever guessing.

The wind was the king of the prairie, Ayanawatta continued. The most important force. He suspected that we had somehow engaged its anger.

He paused in his paddling and took out his flute. He blew a few experimental notes, then began a high, slow tune which made use of the echoes from the distant mountains and turned them back and forth so that once again it seemed the whole of the natural world was singing with him.

The wind dropped suddenly. And as it dropped, Ayanawatta's flute died away. The extraordinary scenery seemed to go on forever, changing as the light changed, until it was close to twilight. The river ahead had begun to rumble and hiss. Ayanawatta said we would have to bypass the rapids tomorrow. Meanwhile we would make camp before sunset, and this time, he promised, he would catch whatever fish the serpent had left us.

In the morning when I awoke Ayanawatta was gone. The only movement was the lazy smoke from his fire, the only sound the distant lapping of water and the melancholy wail of a river bird. I felt the ground shiver under me. Was this the sound of the rapids he had spoken about?

I rose quickly, hardly able to believe I was not experiencing an earthquake. I heard the chirping of frogs and insects, steady, high. I smelled the smoke and the rich, earthy pines, the acrid oaks and sweet ash. I heard a bird flap and dive, and then I heard a disturbance in the water. I looked up and saw a hawk carrying a bird in its talons. I found myself wondering about the magical meaning of what I had seen.

The earth shuddered again, and wood snapped within the forest. I looked for Ayanawatta's bow and arrows, but they were gone. I found one of his lances, still in the bottom of the boat, and armed myself with it. As I turned, however, it became immediately obvious that a stone lance, even a magic one, might not be much use against this newcomer. Out of the thick woods, scattering branches and leaves in all directions, a fantastic apparition loomed over me.

While I was familiar with the Asian use of domestic elephants, I had never seen a man seated on the back of a black woolly mammoth with tusks at least nine feet long curving out over an area of at least twenty feet!

The rider approaching me was clearly a warrior of the region, but with subtle differences of dress, black face paint, shaven head, scalp lock worn long, a lance and a war-shield held in his left hand, his right hand gripping the decorated reins of his huge mount. It was impossible to judge the rider's size, but it was clear the mammoth was not young. The old tusks were splintered and bound but could still very easily kill almost anything which attacked their owner.

My heart thumped with sickening speed. I looked for some advantage. At the last moment the mammoth's trunk rose in a gesture of peace. At the same time the painted warrior raised his palm to reassure me.

The mammoth swung her weight forward and began to lower herself onto her knees as the newcomer slid blithely down her back and landed on the turf. His tone was at odds with his ferocious black mask. "The prophecy told me I would meet my friend Ayanawatta here but only hinted at his companion. I am sorry if I alarmed you. Please forgive the death paint. I've been in a fairly intense dispute."

This thoroughly decorated man had a similar grace of manner to Ayanawatta, but something about his movements was familiar to me. His posture, however, was more brooding. His paint was a black, glowing mask in which two dark rubies burned. I held on to the spear and took a step back. I began to feel sicker still as I recognized him.

Silently, fascinated, I waited for him to approach.