Jeffrey Greggson was one islander who, as yet, had no interest in esthetics or science, the two main preoccupations of his elders. But he heartily approved of the Colony, for purely personal reasons. The sea, never more than a few kilometres away in any direction, fascinated him. Most of his short life had been spent far inland, and he was not yet accustomed to the novelty of being surrounded by water. He was a good swimmer, and would often cycle off with other young friends, carrying his fins and mask, to go exploring the shallower water of the lagoon. At first Jean was not very happy about this, but after she had made a few dives herself; she lost her fear of the sea and its strange creatures and let Jeffrey enjoy himself as he pleased -- on condition that he never swam alone.

The other member of the Greggson household who approved of the change was Fey, the beautiful golden retriever who nominally belonged to George, but could seldom be detached from Jeffrey. The two were inseparable, both by day and -- if Jean had not put her foot down -- by night. Only when Jeffrey went off on his bicycle did Fey remain at home, lying listlessly in front of the door and staring down the road with moist, mournful eyes, her muzzle resting on her paws.

This was rather mortifying to George, who had paid a stiff price for Fey and her pedigree. It looked as if he would have to wait for the next generation -- due in three months -- before he could have a dog of his own. Jean had other views on the subject. She liked Fey, but felt that one hound per house was quite sufficient.

Only Jennifer Anne had not yet decided whether she liked the Colony. That, however, was hardly surprising, for she had so far seen nothing of the world beyond the plastic panels of her cot, and had, as yet, very little suspicion that such a place existed.

George Greggson did not often think about the past: he was too busy with plans for the future, too much occupied by his work and his children. It was rare indeed that his mind went back across the years to that evening in Africa, and he never talked about it with Jean. By mutual consent, the subject was avoided, and since that day they had never visited the Boyces again, despite repeated invitations. They called Rupert with fresh excuses several times a year, and lately he had ceased to bother them. His marriage to Maia, rather to everyone's surprise, still seemed to be flourishing.

One result of that evening was that Jean had lost all desire to dabble with mysteries at the borders of known science. The naive and uncritical wonder that had drawn her to Rupert and his experiments had completely vanished. Perhaps she had been convinced and wanted no more proof: George preferred not to ask her. It was just as likely that the cares of maternity had banished such interests from her mind.

There was no point, George knew, in worrying about a mystery that could never be solved, yet sometimes in the stillness of the night he would wake and wonder. He remembered his meeting with Jan Rodericks on the roof of Rupert's house, and the few words that were all he had spoken with the only human being successfully to defy the Overlords' ban. Nothing in the realm of the supernatural, thought George, could be more eerie than the plain scientific fact that though almost ten years had passed since he had spoken to Jan, that now-far-distant voyager would have aged by only a few days.

The universe was vast, but that fact terrified him less than its mystery. George was not a person who thought deeply on such matters, yet sometimes it seemed to him that men were like children amusing themselves in some secluded playground, protected from the fierce realities of the outer world. Jan Rodricks had resented that protection and had escaped from it -- into no one knew what. But in this matter George found himself on the side of the Overlords. He had no wish to face whatever lurked in the unknown darkness, just beyond the little circle of light cast by the lamp of Science.

"How is it?" said George plaintively, "that Jeff's always off somewhere when I happen to be home? Where's he gone today?"

"I really came home to do some work," said George thoughtfully. "But it's a nice day, and I think I'll go out there and have a swim myself. What kind of fish would you like me to bring back?"

Jean looked up from her knitting -- an archaic occupation which had recently been revived with much success. Such fashions came and went on the island with some rapidity. The main result of this particular craze was that the men had now all been presented with multi-coloured sweaters, far too hot to wear in the daytime but quite useful after sundown.

"He's gone off to Sparta with some friends," Jean replied. "He promised to be back for dinner."

George had never caught anything, and the fish in the lagoon were much too wily to be trapped. Jean was just going to point this out when the stillness of the afternoon was shattered by a sound that still had power, even in this peaceful age, to chill the blood and set the scalp crawling with apprehension. It was the wail of a siren, rising and filling, spreading its message of danger in concentric circles out to sea.

For almost a hundred years the stresses had been slowly increasing, here in the burning darkness deep beneath the ocean's floor. Though the submarine canyon had been formed geological ages ago, the tortured rocks had never reconciled themselves to their new positions. Countless times the strata had creaked and shifted, as the unimaginable weight of water disturbed their precarious equilibrium. They were ready to move again.

The day was quiet and peaceful. There was not a breath of wind, and even the perpetual muttering beyond the reef had sunk to a sullen undertone. A blazing sun hung half-way down the sky, but Jeff's mahogany-brown body was now quite immune to its onslaughts.

Jeff was exploring the rock pools along the narrow Spartan beach -- an occupation he found endlessly absorbing. One never knew what exotic creatures one might find, sheltered here from the waves that marched forever across the Pacific to spend themselves against the reef. It was a fairyland for any child, and at the moment he possessed it all himself, for his friends had gone up into the hills.

Swifter than any tide could ebb, the water was receding from the shore. Jeff watched, deeply puzzled and not in the least afraid, as the wet sands were uncovered and lay sparkling in the sun. He followed the retreating ocean, determined to make the most of whatever miracle had opened up the underwater world for his inspection. Now the level had sunk so far that the broken mast of the old wreck was climbing into the air, its weeds hanging limply from it as they lost their liquid support. Jeff hastened forward, eager to see what wonders would be uncovered next.

Very firmly, something took hold of the beach and gave it a single, sudden jerk. The tremor passed so swiftly that Jeff wondered if he had imagined it. Perhaps it was a momentary giddiness, for all around him remained utterly unchanged. The waters of the lagoon were unruffled, the sky empty of cloud or menace. And then a very strange thing began to happen.

The beach here was a narrow belt of sand, sloping steeply towards the lagoon. Looking down into the glass-clear water, Jeff could see the submerged rocks which were as familiar to him as any formations on the land. About ten metres down, the weed-covered ribs of an ancient schooner curved up towards the world it had left almost two centuries ago. Jeff and his friends had often explored the wreck, but their hopes of hidden treasure had been disappointed. All that they had ever retrieved was a barnacle-encrusted compass.

It was a sucking, gurgling sound, as of a river racing through a narrow channel. It was the voice of the reluctantly retreating sea, angry at losing, even for a moment, the lands it rightfully possessed. Through the graceful branches of the coral, through the hidden submarine caves, millions of tons of water were draining out of the lagoon into the vastness of the Pacific.

It was then that he noticed the sound from the reef. He had never heard anything like it before, and he stopped to think the matter over, his bare feet slowly sinking into the moist sand. A great fish was thrashing in its death agonies a few metres away, but Jeff scarcely noticed it. He stood, alert and listening, while the noise from the reef grew steadily around him.

One of the salvage parties, hours later, found Jeff on a great block of coral that had been hurled twenty metres above the normal water level. He did not seem particularly frightened, though he was upset over the loss of his bicycle. He was also very hungry, as the partial destruction of the causeway had cut him off from home. When rescued he was contemplating swimming back to Athens, and, unless the currents had changed drastically, would doubtless have managed the crossing without much trouble.

Very soon, and very swiftly, they would return.

"Go to sleep, darling, and forget all about it," said Jean. "You're all right now."

Jean burst into tears when her son was restored to her, for she had quite convinced herself that he had been swept out to sea. She had watched with horrified eyes as the black and foam-capped wall of water had moved roaring in from the horizon to smother the base of Sparta in spume and spray. It seemed incredible that Jeff could have reached safety in time.

It was scarcely surprising that he could not give a very rational account of what had happened. When he had eaten and was safely in bed, Jean and George gathered by his side.

Jean and George had witnessed the whole sequence of events when the tsunami hit the island. Though the damage to the low-lying areas of Athens had been severe, there had been no loss of life. The seismographs had been able to give only fifteen minutes' warning, but that had been long enough to get everyone above the danger line. Now the Colony was licking its wounds and collecting together a mass of legends that would grow steadily more hair-raising through the years to come.

"I can't quite remember, but it was something like Jeffrey, get up the hill as quickly as you can. You'll be drowned if you stay here. I'm sure it called me Jeffrey, not Jeff. So it couldn't have been anyone I knew."

"What did it say?"

"I want to get to the bottom of this. Tell me just what happened, Jeff."

"But someone told me to run." Jean and George glanced at each other in mild alarm.

"But it was fun, Mummy," protested Jeff. "I wasn't really frightened."

"That's fine," said George. "You're a brave lad, and it's a good thing you were sensible and ran in time. I've heard about these tidal waves before. A lot of people get drowned because they go out on the uncovered beach to see what's happened."

"Well, I was right down the beach, by that old wreck, when the voice spoke."

"That's what I did," confessed Jeff. "I wonder who it was helped me?"

"Oh, don't bother him now," said Jean anxiously, and with a little too much haste. But George was stubborn.

"You mean -- you imagined you heard something?"

"What do you mean? There wasn't anyone with you. The other boys were up the hill." Jeff looked puzzled.

"Shush! Go on, Jeff."

"Yes -- until I started to climb the hill. Then another funny thing happened. You know the path up the cliff?"

"Well, it wasn't quite like anyone I've ever heard talking before. I think he was a very big man."

"The 'quake must have brought it down," said George.

"I didn't know what to do, and I could hear the wave coming closer. Then the voice said 'Close your eyes, Jeffrey, and put your hand in front of your face. It seemed a funny thing to do, but I tried it. And then there was a great flash -- I could feel it all over -- and when I opened my eyes the rock was gone."

"Was it a man's voice? And where did it come from?"

"It was ever so close beside me. And it sounded like a man. " Jeff hesitated for a moment, and George prompted him.

"Yes."

"I was running up that, because it was the quickest way. I knew what was happening now, for I'd seen the big wave coming in. It was making an awful noise, too. And then I found there was a great big rock m the way. It wasn't there before, and I couldn't get past it."

"Go on -- just imagine that you're back on the beach, and tell us exactly what happened."

"Is that all the voice said?"

"Gone?"

"Don't worry about the bicycle, dear," said Jean, squeezing her, son thankfully. "We'll get you another one. The only thing that matters is that you're safe. We won't worry about how it happened."

That wasn't true, of course, for the conference began immediately they had left the nursery. It decided nothing, but it had two sequels. The next day, without telling George, Jean took her small son to the Colony's child psychologist. He listened carefully while Jeff repeated his story, not in the least over-awed by his novel surroundings. Then, while his unsuspecting patient rejected seriatim the toys in the next room, the doctor reassured Jean.

"That's right -- it just wasn't there. So I started running again, and that's when I nearly burnt my feet, because the path was awful hot. The water hissed when it went over it, but it couldn't catch me then -- I was too far up the cliff. And that's all. I came down again when there weren't any more waves. Then I found that my bike had gone, and the road home had been knocked down."

That evening, Jean passed the verdict on to her husband. He did not seem as relieved as she had hoped, and she put it down to worry over the damage to his beloved theatre. He just grunted "That's fine," and settled down with the current issue of Stage and Studio. It looked as if he had lost interest in the whole affair, and Jean felt vaguely annoyed with him.

"There's nothing on his card to suggest any mental abnormality. You must remember that he's been through a terrifying experience, and he's come out of it remarkably well. He's a highly imaginative child, and probably believes his own story. So just accept it, and don't worry unless there are any later symptoms. Then let me know at once."

But three weeks later, on the first day that the causeway was reopened, George and his bicycle set off briskly towards Sparta. The beach was still littered with masses of shattered coral, and in one place the reef itself seemed to have been breached. George wondered how long it would take the myriads of patient polyps to repair the damage.

For a long time George Greggson stood on that lonely track, staring at the patch of fused rock beneath his feet. He tried to tell himself that it was some freak of the long-dead volcano, but soon abandoned this attempt at self-deception. His mind went back to that night, years ago, when he and Jean had joined that silly experiment of Rupert Boyce's. No one had ever really understood what had happened then, and George knew that in some unfathomable way these two strange events were linked together. First it had been Jean, now her son. He did not know whether to be glad or fearful, and in his heart he uttered a silent prayer:

"Thank you, Karellen, for whatever your people did for Jeff. But I wish I knew why they did it."

There was only one path up the face of the cliff, and when he had recovered his breath George began the climb. A few dried fragments of weed, trapped among the rocks, marked the limit of the ascending waters.

He went slowly down to the beach, and the great white gulls wheeled around him, annoyed because he had brought no food to throw them as they circled in the sky.