Finally she reached a full gallop: a modified two-beat cycle, the two front legs striking almost but not quite together, then the rear two. A four-beat cycle, technically, but not uniform. Beat-beat, beat-beat, at the velocity of racing. Stile enjoyed it; he experienced an exhilaration of speed that was special on a horse—unicorn. Motored wheels could go much faster, of course, but it wasn’t the same. Here, as it were in the top gear, the animal straining to the limit—though this one was not straining, but loafing at a velocity that would have had another one straining—
The unicorn shifted into another gait. It was a five-beat—
Stile was so surprised he almost dropped off. No horse had a five-beat gait! There were only four feet!
No horse—there he was again. He kept forgetting and getting reminded in awkward ways. This gait was awful; he had never before experienced it, and could not accommodate it. BEAT-beat-BEAT-BEAT-beat, and over again, bouncing him in a growing resonance, causing him to lose not his grip but his composure. He felt like a novice again, fouling himself up, his efforts to compensate for the animal’s motions only making it worse. As a harmonic vibration could shake apart a building, this fifth-beat was destroying him. He would fall—and at this breakneck velocity he could . . . break his neck.
Think, Stile, think! he told himself desperately.
Analyze: What is the key to this gait?
His hands were hurting as his clutch on the unicorn’s mane slowly slipped. His thigh muscles were beginning to cramp. Stile was expert—but this creature had his number now. Unless he could get her number too, soon.
Four feet, five beats. One foot had to repeat. Number the steps: one-two-three-four—where was the repeat? Fingers slipping...
BEAT-beat—that sound was less than the others, like a half-step. But half a step had to be completed by—another half-step. Like a man catching his balance when tripped. Two half-steps—that was it. Not necessarily together. The second and fifth. The right rear foot—as though stumbling, throwing off his timing. Compensate—
Stile started to catch on. He shifted his weight to absorb the shock and irregularity. BEAT-absorb-BEAT-BEAT-absorb. It was tricky and unnatural as hell, but his body was finding the dubious rhythm, get-ting the swing. Mostly it was his knowledge of the pattern, of what to expect. No more surprises! His leg muscles relaxed, and his hands stopped slipping.
Neysa felt the change, and knew he had surmounted this challenge too. She turned at speed—and Stile’s in- ertia almost flung him off her side. A gradual turn at high velocity could pack more wallop than a fast turn at low speed. But she had to shift to a normal gallop for the turn, and no equine living could dump Stile with a normal gallop.
Realizing her mistake, the unicorn changed tactics.
She slowed, then suddenly went into a one-beat gait. This was another surprise, in a ride full of them. It was like riding a pogo stick. All four of her feet landed together; then she leaped forward, front feet leading-only to contract to a single four-point landing again.
But Stile had ridden a pogo stick, in the course of his Game experience. He could handle this. “No luck, Neysa!” he cried. “Give up?”
She snorted derisively through her horn. It was al-most as if she understood his words. But of course horses were very perceptive of tone, and responsive to it.
She turned. She had been going north, having curved in the course of her running; now she bore due west. Round five was coming up.
The grass gave way to packed dirt, then to clay, then to something like shale, and finally to rock. Neysa’s hooves struck sparks from the surface, astonishing Stile. She was traveling fast, to be sure—faster than any horse he had raced. It felt like eighty kilometers per hour, but that had to be a distortion of his perception; such a speed would be of interworld championship level, for a horse. Regardless, hooves were not metallic; this animal was not shod, had no metal horseshoes, no nails. Nothing to strike sparks. Yet they were here.
Now she came to the pattern of crevices he had spied from the tree. They loomed with appalling suddenness: deep clefts in the rock whose bottoms could not be seen. Her hooves clicked between cracks unerringly, but Stile didn’t like this. Not at all! One misstep would drop a foot into one of those holes, and at this speed that would mean a broken leg, a tumble, and one man flying through the air to land—where? But all he could do was hang on.
The cracks became more plentiful, forming a treacherous lattice. His vision of the crevices blurred, because they were so close, passing so rapidly; they seemed to writhe in their channels, swelling and shrinking, now twisting as if about to burst free, now merging with others or splitting apart. He had noted a similar effect when riding the Game model train as a child, fixing his gaze on the neighboring tracks, letting them perform their animations as he traveled. But these were not rails, but crevices, getting worse.
Neysa danced across the lattice as Stile watched with increasing apprehension. Now these were no longer mere cracks in a surface; these were islands between gaps. Neysa was actually traversing a chasm, jumping across from stone to stone, each stone a platform rising vertically from the depths. Stile had never seen such a landscape before. He really was in a new world: new in kind as well as in region.
Now Neysa was leaping, using her one-beat gait to bound from one diminishing platform to another. Sometimes all four feet landed together, in a group, almost touching each other; sometimes they were apart, on separate islands. She was obviously conversant with this place, and knew where to place each hoof, as a child knew where to jump amid the squares of a hop-scotch game, proficient from long practice. Perhaps Neysa had mastered this challenge in order to avoid predators. No carnivore could match her maneuvers here, surely; the creature would inevitably misstep and fall between islands, perhaps prodded by the unicorn’s aggressive horn, and that would be the end. So her trick gait made sense: it was a survival mechanism. Probably the five-beat gait had a similar function. What terrain was it adapted to?
Neysa danced farther into the pattern. The islands became fewer, smaller, farther apart. Now Stile could peer into the lower reaches of the crevices, for the sun-light slanted down from almost overhead. Had it been only six hours from the start of this day? It seemed much longer already! The fissures were not as deep as he had feared; perhaps two meters. But they terminated in rocky creases that could wedge a leg or a body, and they were getting deeper as the unicorn progressed.
This was a test of nerve as much as of agility or riding ability.
As it happened. Stile had the nerve. “Let’s face it, Neysa,” he said. He tended to talk to horses; they listened well, politely rotating their pointed furry ears around to fetch in larger scoops of his sound, and they did not often talk back. “We’re in this together. What would I gain by falling off now? A broken leg? If it’s all the same to you, oh prettiest and surest-footed of equines, I’ll just stay on.” He saw her left ear twitch as if shaking off a fly. She heard him, all right, and was not pleased at the confidence his tone exuded.
But the acrobatic challenge was not what the unicorn had come for. Suddenly she leaped—into the depths of a larger crack. It was two meters wide, shallow at the near end, but bearing lower. The sides seemed to close in as she plunged deeper. Where was she going? Stile did not like this development at all.
Neysa swung around a chasm corner and dropped to a lower level. This crack narrowed above; they were in a partial cave, light raying from the top. Cross-cracks intersected often, but the unicorn proceeded straight ahead.