habits of 46 primitive societies. This role was at least partly genuine, for Calindy was really interested in differing life styles; and by some definitions, Titan could indeed be classed as primitive—or, at least, undeveloped.

Thus the supposedly unshockable Terrans were genuinely horrified at encountering families with three—and even fourl–children on Titan. The twentieth century’s millions of skeleton babies still haunted the conscience of the world, and such tragic but understandable excesses as the “Breeder Lynching” campaign, not to mention the burning of the Vatican, had left permanent scars on the human psyche. Duncan could still remember

Calindy’s expression when she encountered her first family of six: outrage contended with curiosity, until both were moderated by Terran good manners.

He had patiently explained the facts of life to her, pointing out that there was nothing eternally sacred about the dogma of Zero Growth, and that

Titan really needed to double its population every fifty years. Eventually she appreciated this logically, but she had never been able to accept it emotionally. And it was emotion that provided the driving force of

Calindy’s life; her will and beauty and intelligence were merely its servants.

For a young Terran, she was not promiscuous. She once told Duncan-and he believed her-that she never had more than two lovers at a time. On Titan, to Duncan’s considerable distress, she had only one.

Even if the Helmers and Makenzies had not been related through Grandma

Ellen, it was inevitable that she would have met Karl, at one of the countless concerts and parties and dances arranged for Mentor’s castaways.

So Duncan could not really blame himself for introducing them; it would have made no difference in the end. Yet even so, he would always wonder…. Karl was then almost twenty-two-a year older than Calindy, though far less experienced. He still possessed the slightly overmuscled build of the native born Terran, but had adapted so well to the lower gravity that he moved more gracefully than most men who had spent their entire lives on

Titan. He seemed to possess the secret of power without clumsiness. And in a quite literal sense, he was the Golden Boy of his generation.

Though he pretended to hate the phrase, Duncan knew that he was secretly proud of the title someone had given him in his teens: “The boy with hair like the sun.” The description could only have been coined by a visitor from Earth. No Titanian would have thought of it-but everyone agreed that it was completely appropriate. For Karl Helmer was one of those men upon whom, for their own amusement, the Gods had bestowed the fatal gift of beauty.

Only years later, and partly thanks to Colin, did Duncan begin to understand all the nuances of the affair. Soon after his twenty-third birthday, the Makenzies received the last Star Day card that Calindy ever sent them.

“I still don’t know if I made a mistake,” Colin said ruefully as he fingered the bright rectangle of paper that had carried its conventional greetings halfway across the Solar System. “But it seemed a good idea at the time.”

“Well, I don’t think it did any harm, in the long run. tv

Cohn looked at him strangely.

“I wonder. Anyway, it certainly didn’t turn out as I expected.”

“And what did you expect?”

It was sometimes a great advantage, and sometimes downright embarrassing, to have a father who was also your thirty-year-older identical twin. He knew all the mistakes you were going to make, because he had made them already. It was impossible to conceal any secrets from him, because his thought processes were virtually the same. In such a situation, the only policy that made any sense was complete honesty, as far as that could be achieved by human beings.

“I’m not quite sure. But the moment I saw Calindy, shining like a nova amid all that gloom and chaos down in the old mine workings, I wanted to learn more about her … wanted to make her part of my life. You

know what I mean.” 48 Duncan could only nod his head in silent agreement.

“Sheela didn’t mind-after all, I’m not a babysnatcherl And we both hoped that Calindy would give you someone to think about besides Karl.”

“I was already getting over that, anyway. It was much too frustrating.”

Colin chuckled, not unsympathetically.

“So I can imagine. Karl was spreading himself pretty thin. Half of Titan was in love with him in those days-still is, for that matter. Which is why we must keep him out of politics. Remind me to tell you about Alcibiades someday.”

“Who?”

“Ancient Greek general-too clever and charming for his own good. Or for anyone else’s.”

“I appreciate your concern,” said Duncan, with only a slight trace of sarcasm. “But that increased my problems a hundred percent. As she made quite clear, I was much too young for Calindy, and of course Karl was now interested only in her. And to make matters worse, they didn’t even mind me sharing their bed as long as I didn’t get in the way. In fact—2’

“Yes?”

Duncan’s face darkened. How strange that he had never thought of this before, yet how obvious it wasl

“Didn’t mind, hell! They enjoyed having me there, just to tease me! At least Karl did.”

It should have been a shattering revelation, yet somehow it did not hurt as much as he would have expected. He must have realized for a long time, without admitting it to himself, that there was a very definite streak of cruelty in Karl. Certainly his lovemaking often lacked tenderness and consideration; there were even times when he had scared Duncan into something approaching impotence. And to do that to a virile sixteen-year-old was no mean feat. “I’m glad you’ve realized that,” said Colin somberly. “You had to find it out for yourself-you wouldn’t have believed us. But whatever Karl did, he certainly paid for it. That breakdown was serious. And, frankly, I don’t believe his

recovery is as complete as the doctors claim.” This was also a new thought to Duncan, and he turned it over in his mind.

Karl’s breakdown was still a considerable mystery, which the Helmer family had never discussed with outsiders. The romantics had a simple explanation: he was heartbroken over the loss of Calindy. Duncan had always found this too hard to accept. Karl was too tough to pine away like some character in an old time melodrama–especially when there were at least a thousand volunteers waiting to console him. Yet it was undeniable that the breakdown had occurred only a few weeks after Mentor had, to everyone’s relief, blasted Earthward.

After that, there had been a complete change in his personality; whenever

Duncan met him in these last few years, he had seemed almost a stranger.

Physically, he was as beautiful as ever-perhaps even more so, thanks to his greater maturity. And he could still be friendly, though there were sudden silences when he seemed to retreat into himself for no apparent reason. But real communication was missing; maybe it had never been there…. No, that was unfair and untrue. They had known many shared moments before

Calindy entered their lives. And one, though only one, after she had left.

That was still the deepest pain that Duncan had ever known. He had been inarticulate with grief when they had made their farewells in the shuttle terminus of Meridian, surrounded by scores of other parting guests. To its great surprise, Titan had suddenly discovered that it was going to miss its young visitors; nearly every one of them was surrounded by a tearful group of local residents.

Duncan’s grief was also, to no small extent, compounded with jealousy. He never discovered how Karl -or Calindy-had managed it, but they flew up in the shuttle together, and made their final farewells on the ship. So when

Duncan glimpsed Calindy for the last time, when she waved back at him from the quarantine barrier, Karl was still with her. In that desolating moment, he did not suppose that he would ever see her again.