Грег Иган - Phoresis

All this time, she’d been so far from the edge of the balcony that the ground had remained out of sight. As she walked forward, the horizon took longer than she expected to appear: it was even farther below her eye-line than the last time. She was afraid to look up at Tvíburi, to compare the angles the two worlds subtended, as if that might drive the point home far more ruthlessly. She was still a long way from the top of the tower, but some kind of dream-logic tugged at her mind, whispering that if she wasn’t careful, she might end up falling toward the wrong world .

Or rather, the right one, sooner than intended.

Rosalind turned back and raised a hand to Joanna, who reciprocated, smiling. It had taken a lot of courage for her friend to be here beside her, and a lot of strength to make it seem that it had taken none at all. Rosalind was glad that they couldn’t speak now; there were no words for a moment like this. She reached up and grasped the glider’s handle bars firmly, then turned away and walked quickly through the opening in the balcony, onto the ledge, and into the sky.

For a moment she descended almost vertically, but then the airflow grew strong enough to tip the glider, and she was facing straight down. Her body continued to harangue her for the unforgivable thing she’d just done, jangling her nerves like a terrified mother screaming at a child caught in an act of suicidal folly, even as the elation induced by the inexplicable lack of a timely impact and agonizing injuries did its best to argue its own case. Both responses were premature—and as the fall stretched on and on, with neither pain nor safety arriving to settle the argument, Rosalind’s instincts began to cede ground to her more considered judgment. Which was a cautious so far, so good .

Below her, patchy red clouds floated above the ice field. The tug of the air on the glider was still weak, and through the handle bars she could feel how little the frame was stressed. It was hard to think of that as anything negative: how kind of the atmosphere to treat her so gently. But sparing her deceleration now could only have two outcomes: a rougher ride when the deeper atmosphere fought to bring her back to terminal velocity… or an even rougher end, if it failed to slow her sufficiently before the ground completed the job.

So be it. This was what the light of Leander had demanded of her. Tvíbura’s atmosphere was much thinner than Tvíburi’s, so the fall that would demonstrate whether or not the gliders could land them safely on the twin world, if they dropped all the way from the halfway point, could start from a much lower altitude here to compensate for that disadvantage. If her measurements and calculations were correct, a jump from the top of level thirty-six would be precisely as dangerous as the crossing itself.

As Rosalind fell past the clouds, the glider began to shudder, and then roll. She shifted her weight, trying to keep it level; it wasn’t tipping very far, but it was lurching back and forth at an alarming rate. Her own skin was oblivious to the turbulence; all she could feel was a pressure and a chill that barely touched her, as if she were lying face down on a slab of ice, but wearing enough clothing to insulate her from most of its effects.

She surveyed the ground below, hunting for familiar features to note their scale and rate of growth, trying to judge her height and speed against the last jump. She spotted a jagged ravine in the ice, farther to her left than she was used to; had some chance wind pushed her to the east, or had the ground itself, whirling around the midpoint between the worlds, outpaced her own lateral velocity, diminished by altitude?

A cluster of low gray hills rose up on her right, ancient rock that must have been fresh soil a million generations ago. A patch of whorled ridges appeared in the ice below her, raked by the low sunlight. Whatever her rate of descent, it was clear now that she was traveling faster over the land than last time. That did make some sense: the glider bluntly opposed her fall, but eased the air aside as she moved forward. And if it had diverted a greater portion than usual of the energy she’d gained into horizontal motion, that might spare her some of the force of impact.

The glider’s rocking grew more violent. Rosalind could feel one of the bracing rods bowing and relaxing under the onslaught. Sustained pressure was one thing, but this repeated flexing was uncomfortably close to her own action when she was trying to snap a thick twig. She wondered if she should risk letting go of one of the handle bars in order to take hold of the threatened rod; after all, she still had the straps around her waist. But then the glider lurched suddenly, sharpening her sense of how dangerously contorted her body might end up if she left even one hand free.

She could hear the rod squeaking now, the high pitch of its complaint cutting through the noise of the wind. The thickening air buffeted the glider with a relentless, random vigor, as if trying to fold and unfold it along every possible line of weakness, never persisting with the same attack for long, but never failing to return to it later.

She coughed to open her throat and inhaled deeply, but even as she was savoring the sweetness of the air and the rush of strength to her limbs, the rod snapped, leaving its two halves dangling uselessly from their connecting points. The glider deformed, with two panels pushing inward just right of her head, then everting again under the force of the wind.

She gazed down at the shuddering blur of the ice field, trying to take comfort from its proximity even as the speed of her descent drained that consolation away. The glider’s frame was twisting, losing symmetry under its new regime, and the wind was both amplifying and exploiting the result. As the glider rolled and pitched, every sudden shift of orientation imposed its own new stresses, distorting the frame a little more.

And the angles were growing larger, the tilts more precipitous. If the glider overturned, it would break apart completely. She’d somersault with the debris for a while before it was scattered by the wind and she was left tumbling through thin air.

Rosalind tightened her left-hand grip, then reached down with her right hand and loosened the strap around her waist. As her body swung down, she reached up and snatched at the right handle bar, catching the end and then forcing her clenched fist rightward into a more secure hold.

She dangled from the handle bars, astonished equally by her own actions and the fact that they seemed to be helping. The glider was still rocking from side to side, but so long as she maintained her grip, she did not believe it would actually overbalance. Wrist straps , she thought, almost calm for a moment. The handle bars needed to be supplemented with wrist straps.

She glanced down at the ground, but struggled to interpret the faint pattern of blue-white streaks rushing by. There were no hills or ravines in sight now, and she was moving across the ice too rapidly to catch any of the finer details she was accustomed to using to gauge her height. Then she felt the sting of wind-borne dirt on her skin, and understood just how near she was.

She tucked her knees toward her head, and managed to force her feet onto the tops of the runners. The glider gleefully took the new distribution of weight as an excuse to start gyrating more wildly again, but before it could come close to overtipping, it slammed into the ice.

It bounced, twice, almost breaking her grip, spraying fine chips of ice onto her face as the runners scraped over the surface like paring knives. Rosalind kept her body rigid, certain that she alone was holding the frame together.

She tried to see where the glider was taking her, but one of the panels that had retained its position blocked her view. Abruptly, she was airborne again, tumbling, and when the glider struck the ice it was upside down. Rosalind felt an impossible tug on her right arm; she released the handle bar and let half of the glider tear itself away.