The Serpent Mage by Greg Bear

cold and winter. He prided himself on his nose — he could smell mustangs from five miles away in a good straight wind — and what he smelled bothered him.
    It didn't belong. It was out of season, that smell.
    Winter. Snow and ice.
    Something glittered by the cinder cone, like the flash from a circle of mirrors. Gorn began to feel spooked. His crusty burned-red arms itched, and his small hairs stood on end. He pinched his nose between two fingers, then blew into his clean white cotton handkerchief.
    The breeze became something out of a musty old refrigerator or freezer — not so much cold as having been kept still and confined for a long time.
    There were horses coming from the direction of the cinder cone — twenty, thirty, maybe as many as fifty, galloping from a direction where they couldn't possibly have been. What he smelled now was enough to send him into the cab of his truck, because the scent was fierce and electric and dangerous. He started the engine and watched the new herd through the windshield.
    They were all gray, hard to see against the sage but for a quality of iridescence more at home in an oyster shell than on a horse.
    And they were coming right for him, up the gentle scrub-covered slope, faster than any horses he had ever seen, gray blurs with long manes. Beautiful animals. If he could catch them (who could possibly own such beautiful horses and let them loose in this godforsaken country?) he could make a good deal more money by changing his tactics, avoiding the knackers and heading straight for the stock buyers in Las Vegas or Reno.
    A quarter mile from his truck, the herd began to divide. His sharp eyes told him the animals were sinewy, tight-muscled, oddly out of proportion compared to the animals he had known all his life. They looked flayed, and their heads were exquisite, more delicately featured than Arabians, wild and energetic and maybe scared by something behind them. Still at a gallop.
    Suddenly, the five or six horses in the lead lifted all their feet from the ground. They were barely a hundred yards from his truck and Gom clearly saw all four legs on each animal curl up and spread out like those ridiculous hunting paintings in rich men's clubs.
    The lead horses became longer, leaner, flying over the ground, not running, their hindquarters getting blurry, their necks stretching out until their heads seemed level with their shoulders —
    "God damn ," Gorn said under his breath.
    Like bright streaks of Navajo silver, all five lead horses merged with the sky and simply vanished.
    And then the five behind.
    In ranks, all of the pearl-colored herd took to the air near his truck and were gone .

    He did not see them come down again.
    Corn sat behind the wheel with the engine running for a quarter hour before he half-heartedly returned his attention to the ordinary animals still down in the middle of the sage scrub.
    What he felt in his chest was something past all pain and feeling.
    Loss. Bereavement. An agonizing sensation of beauty and one important thing long since fled from his life. Gorn did not know what it was.
    But he knew he would spend the rest of that day, and perhaps the next, looking at the sky. Waiting.
    Michael put the packet of letters aside and pressed the bridge of his nose between two fingers.
    His life was dividing in two, and the division was fuzzing rapidly. How long could he keep the parts separated — and how long could he observe, and learn, without acting?
    The sky was clear and bland overhead, an extremely self-assured sky, unlike the Realm's active and ever-changing blueness. Differences. Contrasts are the direct path to knowing .
    He was becoming more and more aware of human variety; in contrast, the Sidhe had seemed almost uniform, lacking the physical and mental differences and distortions endemic to humankind.
    The Sidhe were like thoroughbreds; their lines had been molded across tens of millions of years, with who could tell what kind of strictures and