Just under the surface of the water the sea was warm, weird life showed colors Ross could name, shades he could not. The corals, the animals masquerading as plants, the plants disguised as animals which inhabited the oceans of Terra, had their counterparts here. And the settlers had given them the familiar names, though the crabs, the fish, the anemones, and weeds of the shallow lagoons and reefs were not identical with Terran creatures. The trouble was that there was too much, such a wealth of life to attract the eyes, hold attention, that it was difficult to keep to the job at hand—the search for what was not natural, for what had no normal place here.

As the land seduced the senses and bewitched the off-worlder, so did the sea have its enchantment to pull one from duty. Ross resolutely skimmed by a forest of weaving, waving lace which varied from a green which was almost black to a pale tint he could not truly identify. Among those waving fans lurked ghost-fish, finned swimmers transparent enough so that one could sight, through their pallid sides, the evidences of recently ingested meals.

The Terrans had begun their sweep-search a half hour ago, slipping overboard from a ferry canoe, heading in toward the checkpoint of the finger isle, forming an arc of expert divers, men and girls so at home in the ocean that they should be able to make the discovery Ashe needed—if such did exist.

Mystery built upon mystery on Hawaika, Ross thought as he used his spear-gun to push aside a floating banner of weed in order to peer below its curtain. The native life of this world must always have been largely aquatic. The settlers had discovered only a few small animals on the islands. The largest of which was the burrower, a creature not unlike a miniature monkey in that it had hind legs on which it walked erect and forepaws, well clawed for digging purposes, which it used with as much skill and dexterity as a man used hands. Its body was hairless and it was able to assume, chameleon-like, the color of the soil and rocks where it denned. The head was set directly on its bowed shoulders without vestige of neck; and it had round bubbles of eyes near the top of its skull, a nose which was a single vertical slit, and a wide mouth fanged for crushing the shelled creatures on which it fed. All in all, to Terran eyes, it was a vaguely repulsive creature, but as far as the settlers had been able to discover it was the highest form of land life. The smaller rodentlike things, the two species of wingless diving birds, and an odd assortment of reptiles and amphibians sharing the island were all the burrowers' prey.

A world of sea and islands, what type of native intelligent life had it once supported? Or had this been only a galactic colony, with no native population before the coming of the stellar explorers? Ross hovered above a dark pocket where the bottom had suddenly dipped into a saucer-shaped depression. The sea growth about the rim rippled in the water raggedly, but there was something about its general outline....

Ross began a circumference of that hollow. Allowing for the distortion of the growths which had formed lumpy excrescences or reached turrets toward the surface—yes, allowing for those—this was decidedly something out of the ordinary! The depression was too regular, too even, Ross was certain of that. With a thrill of excitement he began a descent into the cup, striving to trace signs which would prove his suspicion correct.

How many years, centuries, had the slow coverage of the sea life gathered there, flourished, died, with other creatures to build anew on the remains? Now there was only a hint that the depression had other than a natural beginning.

Anchoring with a one-handed grip on a spike of Hawaikan coral—smoother than the Terran species—Ross aimed the butt of his spear-gun at the nearest wall of the saucer, striving to reach into a crevice between two lumps of growth and so probe into what might lie behind. The spear rebounded; there was no breaking that crust with such a fragile tool. But perhaps he would have better luck lower down.

The depression was deeper than he had first judged. Now the light which existed in the shallows vanished. Red and yellow as colors went, but Ross was aware of blues and greens in shades and tints which were not visible above. He switched on his diving torch, and color returned within its beam. A swirl of weed, pink in the light, became darkly emerald beyond as if it possessed the chameleon ability of the burrowers.

He was distracted by that phenomenon, and so he transgressed the diver's rule of never becoming so absorbed in surroundings as to forget caution. Just when did Ross become aware of that shadow below? Was it when a school of ghost-fish burst unexpectedly between weed growths, and he turned to follow them with the torch? Then the outer edge of his beam caught the movement of a shape, a flutter in the water of the gloomy depths.

Ross swung around, his back to the wall of the saucer, as he aimed the torch down at what was arising there. The light caught and held for a long moment of horror something which might have come out of the nightmares of his own world. Afterward Ross knew that the monster was not as large as it seemed in that endless minute of fear, perhaps no bigger than the dolphins.

He had had training in shark-infested seas on Terra, been carefully briefed against the danger from such hunters of the deep and ocean jungles. But this kind of thing had only existed before in the fairy tales of his race as the dragon of old lore. A scaled head with wide eyes gleaming in the light beam with cold and sullen hate, a gaping mouth fang-filled, a horn-set muzzle, that long, undulating neck and, below it, the half-seen bulk of a monstrous body.

His spear-gun, the knife at his waist belt, neither were protection against this! Yet to turn his back on that rising head was more than Ross could do. He pulled himself back against the wall of the saucer. The thing before him did not rush to attack. Plainly it had seen him and now it moved with the leisure of a hunter having no fears concerning the eventual outcome of the hunt. But the light appeared to puzzle it and Ross kept the beam shining straight into those evil eyes.

The shock of the encounter was wearing off; now Ross edged his flipper into a crevice to hold him steady while his hand went to the sonic-com at his waist. He tapped out a distress call which the dolphins could relay to the swimmers. The swaying dragon head paused, held rigid on a stiff, scaled column in the center of the saucer. That sonic vibration either surprised or bothered the hunter, made it wary.

Ross tapped again. The belief that if he tried to escape, he was lost, that only while he faced it so had he any chance, grew stronger. The head was only inches below the level of his flippered feet as he held to the weeds.

Again that weaving movement, the rise of head, a tremor along the serpent neck, an agitation in the depths. The dragon was on the move again. Ross aimed the light directly at the head. The scales, as far as he could determine, were not horny plates but lapped, silvery ovals such as a fish possessed. And the underparts of the monster might even be vulnerable to his spear. But knowing the way a Terran shark could absorb the darts of that weapon and survive, Ross feared to attack except as a last resort.

Above and to his left there was a small hollow where in the past some portion of the growths had been ripped away. If he could fit himself into that crevice, perhaps he could keep the dragon at bay until help arrived. Ross moved with all the skill he had. His hand closed upon the edge of the niche and he whirled himself up, just making it into that refuge as the head lashed at him wickedly. His suspicion that the dragon would attack anything on the run was well founded, and he knew he had no hope of winning to the surface above.

Now he stood in the crevice, facing outward, watching the head darting in the water. He had switched off the torch, and the loss of light appeared to bewilder the reptile for some precious seconds. Ross pulled as far back into the niche as he could, until the point of one shoulder touched a surface which was sleek, smooth, and cold. The shock of that contact almost sent him hurtling out again.

Gripping the spear before him in his right hand, Ross cautiously felt behind him with the left. His finger tips glided over a seamless surface where the growths had been torn or peeled away. Though he could not, or dared not, turn his head to see, he was certain that this was his proof that the walls of the saucer had been fashioned and placed there by some intelligent creature.

The dragon had risen, hovering now in the water directly before the entrance to Ross's hole, its neck curled back against its bulk. It had wide flippers moving like planes to hold it poised. The body, sloping from a massive round of shoulders to a tapering rear, was vaguely familiar. If one provided a Terran seal with a gorgon head and scales in place of fur, the effect would be similar. But Ross was assuredly not facing a seal at this moment.

Slight movement of the flippers kept it as stabilized as if it sprawled on a supporting surface. With the neck flattened against the body, the head curved downward until the horn on its snout pointed the tip straight at Ross's middle. The Terran steadied his spear-gun. The dragon's eyes were its most vulnerable targets; if the creature launched the attack, Ross would aim for them.

Both man and dragon were so intent upon their duel that neither was conscious of the sudden swirl overhead. A sleek dark shape struck down, skimming across the humped-back ridge of the dragon. Some of the settlers had empathy with the dolphins to a high degree, but Ross's own powers of contact were relatively feeble.

Only now he was given an assurance of aid, and a suggestion to attack. The dragon head writhed, twisted as the reptile attempted to see above and behind its own length. But the dolphin was only a streak fast disappearing. And that writhing changed the balance the monster had maintained, pushing it toward Ross.

The Terran fired too soon and without proper aim, so the dart snaked past the head. But the harpoon line half hooked about the neck and seemed to confuse the creature. Ross squirmed as far back as he could into his refuge and drew his knife. Against those fangs the weapon was an almost useless toy, but it was all he had.

Again the dolphin dived in attack on the reptile, this time seizing in its mouth the floating cord of the harpoon and giving it a jerk which jolted the dragon even more off balance, pulling it away from Ross's niche and out into the center of the saucer.

There were two dolphins in action now, Ross saw, playing the dragon as matadors might play a bull, keeping the creature disturbed by their agile maneuvers. Whatever prey came naturally to the Hawaikan monster was not of this type, and the creature was not prepared to deal effectively with their teasing, dodging tactics. Neither had touched the beast, but they kept it constantly striving to get at them.

Though it swam in circles attempting to face its teasers, the dragon did not abandon the level before Ross's refuge, and now and then it darted its head at him, unwilling to give up its prey. Only one of the dolphins frisked and dodged above now as the sonic on Ross's belt vibrated against his lower ribs with its message warning to be prepared for further action. Somewhere above, his own kind gathered. Hurriedly he tapped out in code his warning in return.

Two dolphins busy again, their last dive over the dragon pushing the monster down past Ross's niche toward the saucer's depths. Then they flashed up and away. The dragon was rising in turn, but coming to meet the Hawaikan creature was a ball giving off light, bringing sharp vision and color with it.

Ross's arm swung up to shield his eyes. There was a flash; such answering vibration carried through the waves that even his nerves, far less sensitive than those of the life about him, reacted. He blinked behind his mask. A fish floated by, spiraling up, its belly exposed. And about him growths drooped, trailed lifelessly through the water; while there was a now motionless bulk sinking to the obscurity of the depression floor. A weapon perfected on Terra to use against sharks and barracuda had worked here to kill what could have been more formidable prey.

The Terran wriggled out of the niche, rose to meet another swimmer. As Ashe descended, Ross relayed his news via the sonic. The dolphins were already nosing into the depths in pursuit of their late enemy.

"Look here—" Ross guided Ashe to the crevice which had saved him, aimed the torch beam into it. He had been right! There was a long groove in the covering built up by the growths; a vertical strip some six feet long, of a uniform gray, showed. Ashe touched the find and then gave the alert via the sonic code.

"Metal or an alloy, we've found it!"

But what did they have? Even after an hour's exploration by the full company, Ashe's expert search with his knowledge of artifacts and ancient remains, they were still baffled. It would require labor and tools they did not have, to clear the whole of the saucer. They could be sure only of its size and shape, and the fact that its walls were of an unknown substance which the sea could cloak but not erode. For the length of gray surface showed not the slightest pitting or time wear.

Down at its centermost point they found the dragon's den, an arch coated with growth, before which sprawled the body of the creature. That was dragged aloft with the dolphins' aid, to be taken ashore for study. But the arch itself ... was that part of some old installation?

Torches to the fore, they entered its shadow, only to remain baffled. Here and there were patches of the same gray showing in its interior. Ashe dug the butt of his spear-gun into the sand on the flooring to uncover another oval depression. But what it all signified or what had been its purpose, they could not guess.

"Set up the peep-probe here?" Ross asked.

Ashe's head moved in a slow negative. "Look farther ... spread out," the sonic clicked.

Within a matter of minutes the dolphins reported new remains—two more saucers, each larger than the first, set in a line on the ocean floor, pointing directly to Karara's Finger Island. Cautiously explored, these were discovered to be free of any but harmless life; they stirred up no more dragons.

When the Terrans came ashore on Finger Island to rest and eat their midday meal one of the men paced along the beached dragon. Ashore it lost none of its frightening aspect. And seeing it, even beached and dead, Ross wondered at his luck in surviving the encounter without a scratch.

"I think that this one would be alone," PaKeeKee commented. "Where there is an eater of this size, there is usually only one."

"Mano-Nui!" The girl Taema shivered as she gave to this monster the name of the shark demon of her people. "Such a one is truly king shark in these waters! But why have we not sighted its like before? Tino-rau, Taua ... they have not reported such—"

"Probably because, as PaKeeKee says, these things are rare," Ashe returned. "A carnivore of size would have to have a fairly wide hunting range, yet there's evidence that this thing has laired in that den for some time. Which means that it must have a defined hunting territory allowing no trespassing from others of its species."

Karara nodded. "Also it may hunt only at intervals, eat heavily, and lie quiet until that meal is digested. There are large snakes on Terra that follow that pattern. Ross was in its front yard when it came after him—"

"From now on"—Ashe swallowed a quarter of fruit—"we know what to watch for, and the weapon which will finish it off. Don't forget that!"

The delicate mechanisms of their sonics had already registered the vibrations which would warn of a dragon's presence, and the depth globes would then do the rest.

"Big skull, oversize for the body." PaKeeKee squatted on his heels by the head lying on the sand at the end of the now fully extended neck.

Ross had heretofore been more aware of the armament of that head, the fangs set in the powerful jaws, the horn on the snout. But PaKeeKee's comment drew his attention to the fact that the scale-covered skull did dome up above the eye pits in a way to suggest ample brain room. Had the thing been intelligent? Karara put that into words:

"Rule One?" She went over to survey the carcass.

Ross resented her half question, whether it was addressed to him or mere thinking aloud on her part.

Rule One: Conserve native life to the fullest extent. Humanoid form may not be the only evidence of intelligence.

There were the dolphins to prove that point right on Terra. But did Rule One mean that you had to let a monster nibble at you because it might just be a high type of alien intelligence? Let Karara spout Rule One while backed into a crevice under water with that horn stabbing at her mid-section!

"Rule One does not mean to forego self-defense," Ashe commented mildly. "This thing is a hunter, and you can't stop to apply recognition techniques when you are being regarded as legitimate prey. If you are the stronger, or an equal, yes—stop and think before becoming aggressive. But in a situation like this—take no chances."

"Anyway, from now on," Karara pointed out, "it could be possible to shock instead of kill."

"Gordon"—PaKeeKee swung around—"what have we found here—besides this thing?"

"I can't even guess. Except that those depressions were made for a purpose and have been there for a long time. Whether they were originally in the water, or the land sank, that we don't know either. But now we have a site to set up the peep-probe."

"We do that right away?" Ross wanted to know. Impatience bit at him. But Ashe still had a trace of frown. He shook his head.

"Have to make sure of our site, very sure. I don't want to start any chain reaction on the other side of the time wall."

And he was right, Ross was forced to admit, remembering what had happened when the galactics had discovered the Red time gates and traced them forward to their twentieth-century source, ruthlessly destroying each station. The original colonists of Hawaika had been as giants to Terran pygmies when it came to technical knowledge. To use even a peep-probe indiscreetly near one of their outposts might bring swift and terrible retribution.