They sorted the crash rations into small packs. A blanket of the water-resistant, feather-heavy Ozakian spider silk was cut into a protective covering for Vye. That piece of tailoring occupied them until the graying sky permitted them a full picture of the pocket in which the flitter had landed. The dark foliage of the mountain growth was broken here by a ledge of dark-blue stone on which the flyer rested.  
To the right was a sheer drop, and a land slip had cut away the ledge itself a few feet behind the flitter. There was only a steadily narrowing path ahead, slanting upward.
 
"Can we take off again?" Vye hoped to be reassured that such a feat was possible.
 
"Look up!"
 
Vye backed against the cliff wall, stared up at the sky. Well above them those globes still swam in unwearied circles, commanding the air lanes.
 
Hume had cautiously approached the outer rim of the ledge, was using his distance glasses to scan what might lie below.
 
"No sign yet."
 
Vye knew what he meant. The globes were overhead, but the blue beasts, or any other fauna those balls might summon, had not yet appeared.
 
Shouldering their packs they started along the ledge. Hume had his ray tube, but Vye was weaponless, unless somewhere along their route he could pick up some defensive and offensive arm. Stones had burst the lights of the islet, they might prove as effective against the blue beasts. He kept watch for any of the proper size and weight.
 
The ledge narrowed, one shoulder scraped the cliff now as[61] they rounded a pinnacle to lose sight of the flitter. But the globes continued to hover over them.
 
"We are still traveling in the direction they want," Vye speculated.
 
Hume had gone to hands and knees to negotiate an ascent so steep he had to search for head and toe holds. When they were safely past that point they took a breather, and Vye glanced aloft again. Now the sky was empty.
 
"We may have arrived, or are about to do so," said Hume.
 
"Where?"
 
Hume shrugged. "Your guess is as good as mine. And both of us can be wrong."
 
The steep ascent did not quite reach the top of the cliff around the face of which the ledge curled. Instead their path now leveled off and began to widen out so that they could walk with more confidence. Then it threaded into a crevice between two towering rock walls and sloped downward.
 
A path unnaturally smooth, Vye thought, as if shaped to funnel wayfarers on. And they came out on the rim of a valley, a valley centered with a wood-encircled lake. They stepped from the rock of the passage onto a springy turf which gave elastically to their tread.
 
Vye's sandal struck a round stone. It started from its bed in the black-green vegetation, turned over so that round pits stared eyelessly up at him. He was faced by the fleshless grin of a human skull.
 
Hume went down on one knee, examined the ground growth, gingerly lifted the lace of vertebrae forming a spine. That ended in a crushed break which he studied briefly before he laid the bones gently back into the concealing cover of the mossy stuff.
 
"That was done by teeth!"
 
The cup of green valley had not changed, it was the same as it had been when they had emerged from the crevice. But now every clump of trees, every wind-rippled mound of brush promised cover.
 
Vye moistened his lips, diverted his eyes from the skull.
 
"Weathered," Hume said slowly, "must have been here for seasons, maybe planet years."
 
"A survivor from the L-B?" Yet this spot lay days of travel from that clearing back in the plains.
 
"How did he get here?"[62]
 
"Probably the same way we would have, had we not holed up on that river island."
 
Driven! Perhaps the lone human on Jumala herded up into this dead-end valley by the globes or the blue beasts. "This process must have been in action for some time."
 
"Why?"
 
"I can give you two reasons." Hume studied the nearest trees narrowly. "First—for some purpose, whatever we are up against wants all interlopers moved out of the lowlands into this section, either to imprison them, or to keep them under surveillance. Second—" He hesitated.
 
Vye's own imagination supplied a second reason, a revolting one he tried to deny to himself even as he put it into words:
 
"That broken spine—food...." Vye wanted Hume to contradict him, but the Hunter only glanced around, his expression already sufficient answer.
 
"Let's get out of here!" Vye was fighting down panic with every ounce of control he could summon, trying not to bolt for the crevice. But he knew he could not force himself any farther into that sinister valley.
 
"If we can!" Hume's words lingered direly in his ears.
 
Stones had smashed the globes by the river. If they still waited out there Vye was willing to try and break them with his bare hands, should escape demand such action. Hume must have agreed with those thoughts, he was already taking long strides back to the cliff entrance.
 
But that door was closed. Hume's foot, raised for the last step toward the crevice corridor, struck an invisible obstruction. He reeled back, clutching at Vye's shoulder.
 
"Something's there!"
 
The younger man put out his hand questingly. What his fingers flattened against was not a tight, solid surface, but rather an unseen elastic curtain which gave a little under his prodding and then drew taut again.
 
Together they explored by touch what they could not see. The crevice through which they had entered was now closed with a curtain they could not pierce or break. Hume tried his ray tube. They watched thin flame run up and down that invisible barrier, but not destroy it.
 
Hume relooped the tube. "Their trap is sprung."
 
"There may be another way out!" But Vye was already[63] despondently sure there was not. Those who had rigged this trap would leave no bolt holes. But because they were human and refused to accept the inevitable without a fight, the captives set off, not down into the curve of the cup, but along its slope.
 
Tongues of brush and tree clumps brought about detours which forced them slowly downward. They were well away from the crevice when Hume halted, flung up a hand in silent warning. Vye listened, trying to pick up the sound which had alarmed his companion.
 
It was as Vye strained to catch a betraying noise that he was first conscious of what he did not hear. In the plains there had been squeaking, humming, chitterings, the vocalizing of myriad grass dwellers. Here, except for the sighing of the wind and a few insect sounds—nothing. All inhabitants bigger than a Jumalan fly might have long ago been routed out of the land.
 
"To the left." Hume faced about.
 
There was a heavy thicket there, too stoutly grown for anything to be within its shadow. Whatever moved must be behind it.
 
Vye looked about him frantically for anything he could use as a weapon. Then he grabbed at the long bush knife in Hume's belt sheath. Eighteen inches of tri-fold steel gleamed wickedly, its hilt fitting neatly into his fist as he held it point up, ready.
 
Hume advanced on the bush in small steps, and Vye circled to his left a few paces behind. The Hunter was an expert with ray tube; that, too, was part of the necessary skill of a safari leade............