Sea of Silver Light by Tad Williams

had not exaggerated. The striations that had made the path safe had lost much of their definition, and although the trail itself still seemed substantial, the crispness of its outer edge was gone, as though the stone were some kind of licorice ice cream that had been out of the freezer a little too long.
    "I still wonder why the Other would want to bring us to a place like this," she said quietly to !Xabbu as they started down the trail after Jongleur, "And maybe to that first unfinished world, too." She couldn't help remembering how part of the ground in that other world had suddenly vanished, trapping Martine and shearing off T4b's hand. What if the same instability happened here? She decided not to waste time brooding about something she couldn't prevent.
    T4b's hand, though—that was an interesting anomaly. It had been replaced by another hand, a glowing thing that had done terrible damage to one of the Grail people, who had seemed otherwise invincible. Could T4b's hand somehow have been replaced by a bit of the Other itself, or at least of its ability to shape the network? A wild-card piece of the operating system at the end of his virtual arm?
    She shared the thought with !Xabbu. "But even if the Other made both of these places—carved them out of the raw material of the network, so to speak—it doesn't really tell us anything. If it's been captured or taken over or something by Dread, that might be why this particular construct is starting to lose resolution, but it doesn't explain why that other unfinished world started falling apart underneath us."
    !Xabbu cut her off. "Look here. I do not remember the path being like that before." The trail in front of them was suddenly only wide enough for them to pass single file. "We should save our talking and thinking until we have found a wide place on the trail and stopped for the night."
    "We're not going to sleep on this mountain, are we?" Sam protested. "It only took us a couple of hours to climb up!"
    "Yes," !Xabbu told her, "but I think that was from a spot very high up the mountainside. Going down to the bottom may be a much longer trip."
    "If we make it down safely," Renie said, edging past the narrow space and its much too expansive view of the sheer black mountainside below her feet, "then I won't mind if it takes a week."
     
    Even after hours of plodding descent, they seemed no closer to the bank of white cloud. They were all tired—Renie, who had not slept, was perhaps the weariest of all. It was not surprising that an accident should happen.
    They had reached one of the narrower stretches of trail, not the worst they had seen—in places they had been forced to edge sideways along the path with their backs against the hard stone of the mountainside—but slender enough that two of them could not safely stand side by side. Sam was just behind Renie; !Xabbu and Felix Jongleur were the first and second in line. Klement, who at times had trailed a long way to the rear, was now so close he could reach out and touch the last in line, which for some reason was exactly what he did.
    Sam, startled and frightened by Klement's fingers trailing through her hair, lurched forward, trying to push her way past on Renie's inside shoulder. For a moment the two of them tangled; then, trying to give the girl room, Renie put her foot down too far to the outside and the edge of the trail crumbled beneath her like stale bread. For a moment Renie could only flail her arms, a reflex absolutely useless for anything except to increase the odds of dragging Sam over the side as well. Renie shrieked and then tumbled outward, aware even as her heart seemed to stop that the sight of !Xabbu's shoulder and his head turning—far too late to help—was the last of him she would ever see. Then something closed on her wrist like a manacle and she slammed down against the path with her legs dangling over nothingness, her breath smashed out in one great gasp.
    In the scrambling and shouting of her