Once again the beach was a wide expanse of shingle, drying fast under a sun hotter than any Shann had yet known on Warlock. Summer had taken a big leap forward. The Terrans worked in partial shade below a cliff overhang, not only for the protection against the sun's rays, but also as a precaution against any roving Throg air patrol.

Under Thorvald's direction the curious shell dragged from the sea—if it were a shell, and the texture as well as the general shape suggested that—was equipped with a framework to act as a stabilizing outrigger. What resulted was certainly an odd-looking craft, but one which obeyed the paddles and rode the waves easily.

In the full sunlight the outline of islands was clear-cut—red-and-gray-rock above an aquamarine sea. The Terrans had sighted no more of the sea monsters, and the major evidence of native life along the shore was a new species of clak-claks, roosting in cliff holes and scavenging along the sands, and various queer fish and shelled things stranded in small tide pools—to the delight of the wolverines, who fished eagerly up and down the beach, ready to investigate all debris of the storm.

"That should serve." Thorvald tightened the last lashing, straightening up, his fists resting on his hips, to regard the craft with a measure of pride.

Shann was not quite so content. He had matched the Survey officer in industry, but the need for haste still eluded him. So the ship—such as it was—was ready. Now they would be off to explore Thorvald's Utgard. But a small and nagging doubt inside the younger man restrained his enthusiasm over such a voyage. Fork-tail had come out of the section of ocean which they must navigate in this very crude transport. And Shann had no desire to meet an uninjured and alert fork-tail in the latter's own territory.

"Which island do we head for?" Shann kept private his personal doubts of their success. The outmost tip of that chain was only a distant smudge lying low on the water.

"The largest ... that one with trees."

Shann whistled. Since the night of the storm the wolverines were again more amenable to the very light discipline he tried to keep. Perhaps the fury of that elemental burst had tightened the bond between men and animals, both alien to this world. Now Taggi and his mate padded toward him in answer to his summons. But would the wolverines trust the boat? Shann dared not risk their swimming, nor would he agree to leaving them behind.

Thorvald had already stored their few provisions on board. And now Shann steadied the craft against a rock which served them as a wharf, while he coaxed Taggi gently. Though the wolverine protested, he at last scrambled in, to hunch at the bottom of the shell, the picture of apprehension. Togi took longer to make up her mind. And at length Shann picked her up bodily, soothing her with quiet speech and stroking hands, to put her beside her mate.

The shell settled under the weight of the passengers, but Thorvald's foresight concerning the use of the outrigger proved right, for the craft was seaworthy. It answered readily to the dip of their paddles as they headed in a curve, keeping the first of the islands between them and the open sea for a breakwater.

From the air, Thorvald's course would have been a crooked one, for he wove back and forth between the scattered islands of the chain, using their lee calm for the protection of the canoe. About two thirds of the group were barren rock, inhabited only by clak-claks and creatures closer to true Terran birds in that they wore a body plumage which resembled feathers, though their heads were naked and leathery. And, Shann noted, the clak-claks and the birds did not roost on the same islands, each choosing their own particular home while the other species did not invade that territory.

The first large-sized island they approached was crowned by trees, but it had no beach, no approach from sea level. Perhaps it might be possible to climb to the top of the cliff walls. But Thorvald did not suggest that they try it, heading on toward the next large outcrop of land and rock.

Here white lace patterned in a ring well out from the shore to mark a circle of reefs. They nosed their way patiently around the outer circumference of that threatening barrier, hunting the entrance to the lagoon. Within, there were at least two beaches with climbable ascents to the upper reaches inland. Though Shann noted that the vegetation showing was certainly not luxuriant, the few trees within their range of vision being pallid growths, rather like those they had sighted on the fringe of the desert. Leather-headed flyers wheeled out over their canoe, coasting on outspread wings to peer down at the Terran invaders in a manner which suggested intelligent curiosity.

A full flock gathered to escort them as they continued along the outer line of the reef. Thorvald impatiently dug his paddle deeper. They had explored more than half of the reef now without chancing on an entrance channel.

"Regular fence," Shann commented. One could begin to believe that the barrier had been deliberately reared to frustrate visitors. Hot sunshine, reflected back from the surface of the waves, burned their exposed skin, so they dared not discard their ragged clothing. And the wolverines were growing increasingly restless. Shann did not know how much longer the animals would consent to their position as passengers without raising active protest.

"How about trying the next one?" he asked, knowing at the same time his companion was not in any mood to accept such a suggestion with good will.

The officer made no reply, but continued to use his steer paddle in a fashion which spelled out his stubborn determination to find a passage. This was a personal thing now, between Ragnar Thorvald of the Terran Survey and a wall of rock, and the man's will was as strongly rooted as those water-washed stones.

On the southwestern tip of the reef they discovered a possible opening. Shann eyed the narrow space between two fanglike rocks dubiously. To him that width of water lane seemed dangerously limited, the sudden slam of a wave could dash them against either of those pillars, with disastrous results, before they could move to save themselves. But Thorvald pointed their blunt bow toward the passage with seeming confidence, and Shann knew that as far as the officer was concerned, this was their door to the lagoon.

Thorvald might be stubborn, but he was not a fool. And his training and skill in such maneuvers was proved when the canoe rode in a rising swell in and by those rocks to gain the safety, in seconds, of the calm lagoon. Shann sighed with relief, but ventured no comment.

Now they must paddle back along the inner side of the reef to locate the beaches, for fronting them on this side of the well-protected island were cliffs as formidable as those which guarded the first of the chain at which they had aimed.

Shann glanced now and then over the side of the boat, hoping in these shallows to sight the sea bed or some of the inhabitants of these waters. But there was no piercing that green murk. Here and there nodules of rock projected inches or feet above the surface, awash in the wavelets, to be avoided by the voyagers. Shann's shoulders ached and burned, his muscles were unaccustomed to the steady swing of the paddles, and the fire of the sun stabbed easily through only two layers of ragged cloth to his skin. He ran a dry tongue over dryer lips and gazed eagerly ahead in search of the first of the beaches.

What was so important about this island that Thorvald had to make a landing here? The officer's stories of a native race which they might turn against the Throgs to their own advantage was thin, very thin indeed. Especially now, as Shann weighed an unsupported theory against that ache in his shoulders, the possibility of being marooned on the inhospitable shore ahead, against the fifty probable dangers he could total up with very little expenditure of effort. A small nagging doubt of Thorvald's obsession began to grow in his mind. How could Shann even be sure that that carved disk and Thorvald's hokus-pokus with it had been on the level? On the other hand what motive would the officer have for trying such an act just to impress Shann?

The beach at last! As they headed the canoe in that direction the wolverines nearly brought disaster on them. The animals' restlessness became acute as they sighted and scented the shore and knew that they were close. Taggi reared, plunged over the side of the craft, and Shann had just time to fling his weight in the opposite direction as a counterbalance when Togi followed. They splashed shoreward while Thorvald swore fluently and Shann grabbed to save the precious supply bag. In a shower of gravel the animals made land and humped well up on the strand before pausing to shake themselves and splatter far and wide the burden of moisture transported by their shaggy fur.

Ashore, the canoe became a clumsy burden and, light as the craft was, both of the men sweated to get it up on the beach without snagging the outrigger against stones and brush. With the thought of a Throg patrol in mind they worked swiftly to cover it.

Taggi raised an egg-patterned snout from a hollow and licked at the stippling of greenish yolk matting his fur. The wolverines had wasted no time in sampling the contents of a wealth of nesting places beginning just above the high-water mark, cupping two to four tough-shelled eggs in each. Treading a path among those clutches, the Terrans climbed a red-earthed slope toward the interior of the island.

They found water, not the clear running of a mountain spring, but a stalish pool in a stone-walled depression on the crest of a rise, filled by the bounty of the rain. The warm liquid was brackish, but satisfied in part their thirst, and they drank eagerly.

The outer cliff wall of the island was just that, a wall, for there was an inner slope to match the outer. And at the bottom of it a showing of purple-green foliage where plants and stunted trees fought for living space. But there was nothing else, though they quartered that growing section with the care of men trying to locate an enemy outpost.

That night they camped in the hollow, roasted eggs in a fire, and ate the fishy-tasting contents because it was food, not because they relished what they swallowed. Tonight no cloud bank hung overhead. A man, gazing up, could see the stars. The stars and other things, for over the distant shore of the mainland they sighted the cruising lights of a Throg ship and waited tensely for that circle of small sparkling points to swing out toward their own hiding hole.

"They haven't given up," Shann stated what was obvious to them both.

"The settler transport," Thorvald reminded him. "If they do not take a prisoner to talk her in and allay suspicion, then—" he snapped his fingers—"the Patrol will be on their tails, but quick!"

So just by keeping out of Throg range, they were, in a way, still fighting. Shann settled back, his tender shoulders resting against a tree hole. He tried to count the number of days and nights lying behind him now since that early morning when he had watched the Terran camp die under the aliens' weapons. But one day faded into another so that he could remember only action parts clearly—the attack on the grounded scoutship, the sortie they had made in turn on the occupied camp, the dust storm on the river, the escape from the Throg ship in the mountain crevice, and their meeting with the hound. Then that storm which had driven them to seek cover after their curious experience with the disk. And now this day when they had safely reached the island.

"Why this island?" he asked suddenly.

"That carved piece was found here on the edge of this valley," Thorvald returned matter-of-factly.

"But today we found nothing at all——"

"Yet this island supplies us with a starting point."

A starting point for what? A detailed search of all the islands, great and small, in the chain? And how did they dare continue to paddle openly from one to the next with the Throgs sweeping the skies? They would have provided an excellent target today as they combed that reef for an hour or more. Wearily, Shann spread out his hands in the very faint light of their tiny fire, poked with a finger tip at smarting points which would have been blisters had those hands not known a toughening process in the past. More paddling tomorrow? But that was tomorrow, and at least they need not worry tonight about any Throg attack once they had doused the fire, an action which was now being methodically attended to by Thorvald. Shann pushed down on the bed of leaves he had heaped together. The night was quiet. He could hear only the murmur of the sea, a lulling croon of sound to make one sleep deep, perhaps dreamlessly.

Sun struck down, making a dazzle about him. Shann turned over drowsily in that welcome heat, stretching a little as might a cat at ease. Then he really awoke under the press of memory, and the need for alertness rode him once more. Beaten-down grass, the burnt-out embers of last night's fire were beside him. But of Thorvald and the wolverines there were no signs.

Not only did he now lie alone, but he was possessed by the feeling that he had not been deserted only momentarily, that Taggi, Togi and the Survey officer were indeed gone. Shann sat up, got to his feet, breathing faster, a prickle of uneasiness spreading in him, bringing him to that inner slope, up it to the crest from which he could see that beach where last night they had concealed the canoe.

Those lengths of brush and tufts of grass they had used for a screen were strewn about as if tossed in haste. And not too long before....

For the canoe was out in the calm waters within the reef, the paddle blade wielded by its occupant flashing brightly in the sun. On the shingle below, the wolverines prowled back and forth, whining in bewilderment.

"Thorvald——!"

Shann put the full force of his lungs into that hail, hearing the name ring from one of the small peaks at his back. But the man in the boat did not turn his head; there was no change in the speed of that paddle dip.

Shann leaped down the outer slope to the beach, skidding the last few feet, saving himself from going headfirst into the water only by a painful wrench of his body.

"Thorvald!" He tried calling again. But that head, bright under the sun did not turn; there was no answer. Shann tore at his clothes and kicked off his boots.

He did not think of the possibility of lurking sea monsters as he plunged into the water, swam for the canoe edging along the reef, plainly bound for the sea gate to the southwest. Shann was not a powerful swimmer. His first impetus gave him a good start, but after that he had to fight for each foot he gained, and the fear grew in him that the other would reach the reef passage before he could catch up. He wasted no more time trying to hail Thorvald, putting all his breath and energy into the effort of overtaking the craft.

And he almost made it, his hand actually slipping along the log which furnished the balancing outrigger. As his fingers tightened on the slimy wood he looked up, and loosed that hold again in time perhaps to save his life.

For when he ducked to let the water cover his head in an impromptu half dive, Shann carried with him a vivid picture, a picture so astounding that he was a little dazed.

Thorvald had stopped paddling at last, because that paddle had to be put to another use. Had Shann not released his hold on the log and gone under water, that crudely fashioned piece of wood might, have broken his skull. He saw only too clearly the paddle raised in both hands as an ugly weapon, and Thorvald's face, convulsed in a spasm of rage which made it as inhuman as a Throg's.

Sputtering and choking, Shann fought up to the air once more. The paddle was back at the task for which it had been carved, the canoe was underway again, its occupant paying no more attention to what lay behind than if he had successfully disposed of the man in the water. To follow would be only to invite another attack, and Shann might not be so lucky next time. He was not good enough a swimmer to try any tricks such as oversetting the canoe, not when Thorvald was an expert who could easily finish off a fumbling opponent.

Shann swam wearily to shore where the wolverines waited, unable yet to make sense of that attack in the lagoon. What had happened to Thorvald? What motive had led the other to leave Shann and the animals on this island, the island Thorvald had called a starting point in his search for the natives of Warlock? Or had every bit of that tall tale been invented by the Survey officer for some obscure purpose of his own, certainly no sane purpose? Against that logic Shann could only set the carved disk, and he had only Thorvald's word that that had been discovered here.

He dragged himself out of the water on his hands and knees and lay, winded and gasping. Taggi came to lick his face, nuzzle him, making a small, bewildered whimpering. While above, the leather-headed birds called and swooped, fearful and angry for their disturbed nesting place. The Terran retched, coughed up water, and then sat up to look around.

The spread of lagoon was bare. Thorvald must have rounded the south point of land and be very close to the reef passage, perhaps through it by now. Not stopping for his clothes, Shann started up the slope, crawling part of the way on his hands and knees.

He reached the crest again and got to his feet. The sun made an eye-dazzling glitter of the waves. But under the shade of his hands Shann saw the canoe again, beyond the reef, heading on out along the island chain, not back to shore as he had expected. Thorvald was still on the hunt, but for what? A reality which existed, or a dream in his own disturbed brain?

Shann sat down. He was very hungry, for that adventure in the lagoon had sapped his strength. And he was a prisoner along with the wolverines, a prisoner on an island which was half the size of the valley which held the Survey camp. As far as he knew, his only supply of drinkable water was that tank of evil-smelling rain which would be speedily evaporated by a sun such as the one now beating down on him. And between him and the shore was the sea, a sea which harbored such creatures as the fork-tail he had watched die.

Thorvald was still steadily on course, not to the next island in the chain, a small, bare knob, but to the one beyond that. He could have been hurrying to a meeting. Where and with what?

Shann got to his feet, started down to the beach once more, sure now that the officer had no intention of returning, that he was again on his own with only his wits and strength to keep him alive—alive and somehow free of this water-washed prison.