Dr. Yehudi ben Mohammed did not look as if he belonged in a modern hospital, surrounded by flickering life-function displays, Comsole read-outs, whispering voices from hidden speakers, and all the aseptic technology of life and death. In his spotless white robes, with the double circlet of gold cord around his headdress, he should have been holding court in a desert tent, or scanning the horizon from the back of his camel for the first glimpse of an oasis.

Duncan remembered how one of the younger doctors had com men ed, during his first visit: “Sometimes I think El Hadj believes he’s a reincarnation of

Saladin and Lawrence of Arabia.” Although Duncan did not understand the full flavor of the references, this was obviously said more in affectionate jest than in criticism. Did the surgeon, he wondered, wear those robes in the operating theater? They would not be inappropriate there; and certainly they did not interfere with the feline grace of his movements.

“I’m glad,” said Dr. Yehudi, toying with the jeweled dagger on his elaborately inlaid desk-the two touches of antiquity in an otherwise late-twenty-third century environment– ~‘that you’ve finally made up your mind. The—ah-delay has caused certain problems but we’ve overcome them. We now have four perfectly viable embryos, and the first will be trans planted in a week. The others will be kept as backups, in case of a rejection-though that is now very rare.”

And what will happen to the unwanted three? Duncan asked himself, and shied away from the answer. One human being had been created who would

never otherwise have existed. That was the positive side; 291 better to forget the three ghosts who for a brief while had hovered on the borders of reality. Yet it was hard to be coldly logical in matters like this. As he stared across the intricate arabesques, Duncan wondered at the psychology of the calm and elegant figure whose skillful hands had controlled so many destinies. In their own small way, on their own little world, the Makenzies had played at God; but this was something beyond his understanding.

Of course, one could always take refuge in the cold mathematics of reproduction. Old Mother Nature had not the slightest regard for human ethics or feelings. In the course of a lifetime, every man generated enough spermatozoa to populate the entire Solar System, many times over-and all but two or three of that potential multitude were doomed. Had anyone ever gone mad by visualizing each ejaculation as a hundred million murders?

Quite possibly; no wonder that the adherents of some old religions had refused to look through the microscope…. There were moral obligations and uncertainties behind every act. In the long run, a man could only obey the promptings of that mysterious entity called Conscience and hope that the outcome would not be too disastrous.

Not, of course, that one could ever know the final results of any actions.

Strange, thought Duncan, how he had resolved the doubts that had assailed him when he first came to the island. He had learned to take the broader view, and to place the hopes and aspirations of the Makenzies in a wider context. Above all, he had seen the dangers of overreaching ambition; but the lesson of Karl’s fate was still ambiguous and would give him cause to wonder all his life.

With a mild sense of shock, Duncan realized that he had already signed the legal documents and was returning them to Dr. Yehudi. No matter; he had read them carefully and knew his responsibilities. “I, Duncan Makenzie, resident of the satellite Titan presently in orbit around the planet

Saturn” (when did the lawyers think it was going to run away?) “do

hereby accept guardianship of one cloned male 292 child, identified by the chromosome chart herewith attached, and will to the best of my ability .. …. etc.” etc.” etc.Perhaps the world would have been a better place if the parents of normally conceived children had been forced to sign such a contract. This thought, however, was some hundred billion births too late.

The surgeon flowed upward to his full commanding two meters in a gesture of dismissal which, from anyone else, would have seemed slightly discourteous.

But not here, for El Hadj had much on his mind. All the while they had been talking, his eyes had seldom strayed from the pulsing lines of life and death on the read-outs that covered almost one whole wall of his office.

In the main hall of the Administration Building, Duncan paused for a moment before the giant, slowly rotating DNA helix which dominated the entrance.

As his gaze roamed along the spokes of the twisted ladder, contemplating its all-but-infinite possibilities, he could not help thinking again of the pentominoes that Grandma Ellen had set out before him years ago. There were only twelve of those shapes-yet it would take the lifetime of the universe to exhaust their possibilities. And here was no mere dozen, but billions upon billions of locations to be filled by the letters of the genetic code.

The total number of combinations was not one to stagger the mind-because there was no way whatsoever in which the mind could grasp even the faintest conception of it. The number of electrons required to pack the entire cosmos solid from end to end was virtually zero in comparison.

Duncan stepped out into the blazing sunlight, waited for his dark glasses to adjust themselves, and set off in search of Dr. Todd, guide and friend of his previous visit. He would not be leaving for another four hours, and there was one major item of business still to be settled.

Luckily, as Sweeney Todd explained, there was no need to go out to the

Reef.

“I can’t imagine why you’re interested in those ugly beasts. But

you’ll find some on a patch of dead coral at the end of that groin; not much else will live there. The water’s only a meter deep-you won’t even need flippers, just a strong pair of shoes. If you do step on a stonefish, your screams will bring us in time to save your life-though you may wish we hadn’t.”

That was not very encouraging, but ten minutes later Duncan was cautiously walking out into the shallows, bent double as he peered through his borrowed face mask.

There was none of the beauty here that he had seen on the approach to

Golden Reef. The water was crystal clear, but the sea bed was a submarine desert. It was mostly white sand, mingled with broken pieces of coral, like the bleached bones of tiny animals. A few small, drably colored fish were swimming around, and others stared at him with anxious, unfriendly eyes from little burrows in the sand. Once, a brilliantly blue creature like a flattened eel came darting at him and, to his great surprise, gave him a painful nip before he chased it away. It was every bit of three centimeters long, and Duncan, who had never heard of cleaning symbiosis, worried about poison for a few minutes. However, he felt no pangs of imminent dissolution, so pushed his way onward through the tepid water.

The concrete groin-part of the island’s defense against the ceaseless erosion of the waves -stretched out for a hundred meters from the shore and then disappeared beneath the surface. Near its seaward end,

Duncan came across a pile of jumbled rocks, perhaps hurled up by some storm. They must have been here for many years, for they were cemented together with barnacles and small, jagged oysters. Among their caves and crevices, Duncan found what he was seeking.

Each sea urchin appeared to have hollowed out its own cavity in the hard rock; Duncan could not imagine how the creatures had performed this remarkable feat of burrowing. Anchored securely in place, with only a bristling frieze of black spines exposed to the outer world, they were invulnerable to all enemies except Man. But Duncan wished them no harm, and this time had not even brought a knife. He had seen