“I repeat, Majesty — we can fly to Overland.”

Glo’s words were followed by an air-whispering silence during which Toller, bemused with wonder, looked down at his brother to see if — as before — the talk of flying to Overland had come as a shock to him. Lain appeared nervous and ill at ease, but not at all surprised. He and Glo must have been in collaboration, and if Lain believed that the flight could be made — then it could be made! Toller felt a stealthy coolness spread down his spine to the accompaniment of what for him was a totally new intellectual and emotional experience. I have a future, he thought. I have discovered why I am here…

“Tell us more, Lord Glo,” the King said. “This hot air balloon you speak of — has it been designed?”

“Not only has it been designed, Majesty — the archives show that an example was actually fabricated in the year 2187. It was successfully flown several times that year by a philosopher called Usader, and it is believed — although the records are… hmm… vague on this point — that in 2188 he actually attempted the Overland flight.”

“What happened to him?”

“He was never heard of again.”

“That hardly inspires confidence,” Chakkell put in, speaking for the first time. “It’s hardly a record of achievement.”

“That depends on one’s viewpoint.” Glo refused to be discouraged. “Had Usader returned a few days later one might be entitled to describe his flight as a failure. The fact that he did not return could indicate that he had succeeded.”

Chakkell snorted. “More likely that he died!”

“I’m not claiming that such an ascent would be easy or without its share of… hmm… risks. My contention is that our increased scientific knowledge could reduce the risks to an acceptable level. Given sufficient determination — and the proper financial and material resources — we can produce ships capable of flying to Overland.”

Prince Leddravohr sighed audibly and shifted in his chair, but refrained from speaking. Toller guessed that the King had placed powerful restraints on him before the meeting began.

“You make it all sound rather like an aftday jaunt,” King Prad said. “But isn’t it a fact that Land and Overland are almost five-thousand miles apart?”

“The best triangulations give a figure of 4,650 miles, Majesty. Surface to surface, that is.”

“How long would it take to fly that distance?”

“I regret I cannot give a definite answer to that question at this stage.”

“It’s an important question, isn’t it?”

“Undoubtedly! The speed of ascent of the balloon is of fundamental importance, Majesty, but there are many variables to be… hmm… considered.” Glo signalled for Lain to open his roll of paper. “My chief scientist, who is a better mathematician than I, has been working on the preliminary calculations. With your consent, he will explain the problem.”

Lain spread out a chart with trembling hands, and Toller was relieved to see that he had had the foresight to draw it on a limp cloth-based paper which quickly lay flat. Part of it was taken up by a scale diagram which illustrated the sister worlds and their spatial relationships; the remainder was given over to detailed sketches of pear-shaped balloons and complicated gondolas. Lain swallowed with difficulty a couple of times and Toller grew tense, fearing that his brother was unable to speak.

“This circle represents our own world… with its diameter of 4,100 miles,” Lain finally articulated. “The other, smaller circle represents Overland, whose diameter is generally accepted as being 3,220 miles, at its fixed point above our equator on the zero meridian, which passed through Ro-Atabri.”

“I think we all learned that much basic astronomy in our infancy,” Prad said. “Why can’t you say how long the journey from the one to the other will take?”

Lain swallowed again. “Majesty, the size of the balloon and the weight of the load we attach to it will influence the free ascent speed. The difference in temperature between the gases inside the balloon and the surrounding atmosphere is another factor, but the most important governing factor is the amount of crystals available to power the jets.

“Greater fuel economy would be achieved by allowing the balloon to rise to its maximum height — slowing down all the while — and not using the jets until the gravitational pull of Land had grown weak. That, of course, would entail lengthening the transit time and therefore increasing the weight of food and water to be carried, which in turn would.…”

“Enough, enough! My head swims!” The King held out both his hand, fingers slightly crooked as though cradling an invisible balloon. “Settle your mind on a ship which will carry, say, twenty people. Imagine that crystals are reasonably plentiful. Now, how long will it take that ship to reach Overland? I don’t expect you to be precise — simply give me a figure which I can lodge in my cranium.”

Lain, paler than ever, but with growing assurance, ran a fingertip down some columns of figures at the side of his chart. “Twelve days, Majesty.”

“At last!” Prad glanced significantly at Leddravohr and Chakkell. “Now — for the same ship — how much of the green and purple will be required?”

Lain raised his head and stared at the King with troubled eyes. The King gazed back at him, calmly and intently, as he waited for his answer. Toller sensed that wordless communication was taking place, that something beyond his understanding was happening. His brother seemed to have transcended all his nervousness and irresolution, to have acquired a strange authority which — for the moment, at least — placed him on a level with the ruler. Toller felt a surge of family pride as he saw that the King appeared to acknowledge Lain’s new stature and was prepared to give him all the time he needed to formulate his reply.

“May I take it, Majesty,” Lain said at length, “that we are talking about a one-way flight?”

The King’s white eye narrowed. “You may.”

“In that case, Majesty, the ship would require approximately thirty pounds each of pikon and halvell.”

“Thank you. You’re not going to quibble over the fact that a higher proportion of halvell gives the best result in sustained burning?”

Lain shook his head. “Under the circumstances — no.”

“You are a valuable man, Lain Maraquine.”

“Majesty, I don’t understand this,” Glo protested, echoing Toller’s own puzzlement. “There is no conceivable reason for providing a ship with only enough fuel for one transit.”

“A single ship, no,” the King said. “A small fleet, no. But when we are talking about.…“He turned his attention back to Lain. “How many ships would you say?”

Lain produced a bleak smile. “A thousand seems a good round figure, Majesty.”

“A thousand!” There was a creaking sound from Glo’s cane frame as he made an abortive attempt to stand up, and when he spoke again an aggrieved note had crept into his voice. “Am I the only person here who is to be kept in ignorance of the subject under discussion?”

The King made a placating gesture. “There is no conspiracy, Lord Glo — it’s merely that your chief scientist appears to have the ability to read minds. It would please me to learn how he divined what was in my thoughts.”

Lain stared down at his hands and spoke almost abstractedly, almost as though musing aloud. “For more than two-hundred days I have been unable to obtain any statistics on agricultural output or ptertha casualties. The official explanation was that the provincial administrators were too severely overworked to prepare their returns — and I have been trying to persuade myself that such was the case — but the indicators were already there, Majesty. In a way it is a relief to have my worst fears confirmed. The only way to deal with a crisis is to face up to it.”

“I agree with you,” Prad said, “but I was concerned with avoiding a general panic, hence the secrecy. I had to be certain.”