Imperial Earth

Loch Hellbrew and the canyon that led into it, so it presented her with a 180-degree panorama of Titan’s most picturesque landscape. Sometimes, when storms raged through the mountains, the view disappeared for hours behind clouds of ammonia crystals. But today the weather was clear and Duncan could see for at least twenty kilometers.

“What’s happening over there?” he asked.

At first, he had thought it was one of the fire fountains that sometimes erupted in unstable areas; but in that case the city would have been in danger, and he would have heard of it long ago. Then he

realized that the brilliant yet smoky column of light burning steadily on the hill crest three or four kilometers away could only be man-made.

“There’s a fusor running over at Huygens. I don’t know what they’re doing, but that’s the oxygen burn off29

“Oh, one of Armand’s projects. Doesn’t it annoy you?99

“No-I think it’s beautiful. Besides, we need the water. Look at those rain clouds … real rain. And I think there’s something growing over there. I’ve noticed a change in color on the rocks since that flame started burning.”

“That’s quite possible-the bioengineering people will know all about it.

One day you may have a forest to look at, instead of all this bare rock.”

He was joking, of course, and she knew it. Except in very restricted areas, no vegetation could grow here in the open. But experiments like this were a beginning, and one day … Over there in the mountain, a hydrogen fusion plant was at work, melting down the crust of Titan to release all the elements needed for the industries of the little world. And as half that crust consisted of oxygen, now needed only in very small quantities in the closed-cycle economies of the cities, it was simply allowed to burn off.

“Do you realize, Duncan,” said Grandma suddenly, “how neatly that flame symbolizes the difference between Titan and Earth?”

“Well, they don’t have to melt rocks there to get everything they need.” 91 was thinking of something much more fundamental. If a Terran wants a fire, he ignites a jet of hydrocarbons and lets it burn. We do exactly the opposite. We set fire to a jet of oxygen, and let it burn in our hydro methane atmosphere.”

This was such an elementary fact of life-indeed an ecological platitude-that Dqmcan felt disappointed; he had hoped for some more startling revelation. His face must have reflected his thoughts, for

Grandma gave him no chance to comment.

“What I’m trying to tell you,” she said, “is that it may not be as easy

for you to adjust to Earth as you imagine. You may know-or think you know what conditions are like there, but that knowledge isn’t based on experience. When you need it in a hurry, it won’t be there. Your Titan instincts may give the wrong answers. So act slowly, and always think twice before you move.”

“I’ve no choice about acting slowly-my Titan muscles will see to that.”

“How long will you be gone?”

“About a year. My official invitation is for two months, but now the trip’s being paid for, I’ll have funds for a much longer stay. And it seems a pi 7, to waste the opportunity, since it’s my only one.”

He tried to keep his voice as cheerfully optimistic as he could, though he knew perfectly well the thoughts that must be passing through Grandma’s mind. They were both aware that this might be their last meeting. One hundred fourteen was not an excessive age for a woman-but, truly, what did

Grandma have to live for? The hope of seeing him again, when he returned from Earth? He liked to think so…. And there was another matter, never to be referred to, yet hovering in the background. Grandma knew perfectly well the main purpose of his visit to Earth, and the knowledge must, even after all these years, be like a dagger in her heart. She had never forgiven

Malcolm; she had never accepted Colin; would she continue to accept him when he returned with little

Malcolm?

Now she was hunting around, with a clumsiness quite unlike her normal precise movements, in one of the cubbyholes of her work desk.

“Here’s a souvenir to take with you.”

“What-oh, it’s beautiful!” He was not being excessively polite; sheer surprise had forced the reaction from him. The flat, crystal-lidded box he was now holding in his hands was, indeed, one of the most exquisite works of geometrical art he had ever seen. And Grandma could not have chosen any single object more evocative of his youth and of the world that, though he was now about to leave it, must always be his

home. As he stared at the mosaic of colored stones that 31 exactly filled the little box, greeting each of the familiar shapes like an old friend, his eyes misted and the years seemed to roll away. Grandma had not changed; but he was only ten….

A CROSS OF TITANITE

I I You’re old enough now, Duncan, to understand this game … though it’s very much more than a game.1p

Whatever it is, thought Duncan, it doesn’t look very exciting. What can you do with five identical squares of white plastic, a couple of centimeters on a side?