The woman looked up, beaming with surprise and delight.

     Around her, the tiny humanoid figures, each less than an inch tall, went about their normal businesses, unaware of her towering presence or that of the new arrival. They were all true sapient beings, living real lives, unaware that they had been created solely for the amusement of the invisible giants who moved among them. Watching the rise and fall of empires, placing bets on the outcome of wars, occasionally focusing on the activities of individuals with all the rapt attention of soap opera addicts.

     They were forgotten now, though, as the woman sprang up from her crouching position and ran to the newcomer, throwing herself into his arms and crushing her body to his. "Tak, my beloved!" she cried into his shoulder, her head swimming with the fresh sweat smell of him while he stroked her silky soft hair. "I've missed you! So much time without you!" With an act of will she evaporated their clothes, leaving them naked together, and she pressed her breasts hard against his hairy chest. "Now! Quickly! Right here on the grass!"

     Tak almost yielded. His desire for her was almost overwhelming in its intensity. It would be good, so good, but... But it could be better! "Not here," he said therefore. "Come see my new Realm. I made it just for you, as a gift. Almost as good as your country of dreams made true."

     She pulled back just enough to look into his face, her eyes glowing. She loved gifts. "For me?" she breathed in delight. "Show it to me! Oh show it to me! Right now!"

     Tak grinned, ignoring the miniature landscape all around him with its miniature inhabitants with the casual disregard of someone who'd seen it a thousand times before. "Okay," he chuckled and, with a thought, he summoned a doorway, standing alone in the middle of the miniature rolling meadows. "After you," he offered, gesturing her towards it with one hand.

     With a girlish shriek of delight she ran towards it, unmindful of the tiny people inhabiting the land below her, her bare feet crushing one of their little conical huts. The inhabitants themselves were pretty tough and could easily survive being trodden on, but they were sorely puzzled by the havoc caused by something they had been conditioned not to see.

     She grasped the doorhandle and flung the door open, gasping in wonder at what she saw. Stepping through, she found herself standing on the surface of a sphere maybe a hundred yards across. The surface was a jungle of twisting vines bearing large, rhubarb like leaves and heavily ribbed fruit the size of marrows. In the sky above, other spheres sporting similar growths drifted slowly, orbiting around one another and around a central glowing mass; the sun of this strange solar system.

     Staring around in wonder, she counted over a hundred 'worlds. Some larger than the one she was standing on, some smaller. Some spinning close to the 'sun', others drifting lazily far from it. Some in almost perfectly circular orbits, taking perhaps five minutes for one complete revolution, others diving in and soaring back out in highly elliptical paths. As she watched, two globes passed close to each other, almost close enough for their vegetable growths to become entangled. They sped up as they approached, then whipped past each other in wildly curving paths, one dropping down closer to the sun, the other hurled at great speed far out into space. As she watched, it shrank into the distance, eventually disappearing into the cloud of sooty dust that surrounded the system at a distance of several miles.

     A few minutes later, she suspected, it would reappear, zooming in from the other direction. Many of the Realms they created for their amusement were contained in spaces that wrapped around, making them finite in size but unbounded. The dust was to prevent them from seeing the backs of their heads everywhere they looked.

     She gave a gasp of wonder at the spectacle and began to rise up into the air, eager to fly around and explore the place properly, but Tak grabbed her ankle and pulled her back down, wagging a finger at her. "Now now," he said, grinning, delighted by her reaction to his creation. "No cheating. If you want to fly around, you have to do it this way."

     He reached out for one of the large fruits and pulled it free with a twist of his wrist. "These contain a quantity of compressed gas, which you release by pressing here." He squeezed a pair of lighter spots near the bulbous end and the hiss of escaping gas came from the severed stalk. Aimed downwards, it lifted him a few feet above the surface of the verdant moonlet and it took a couple of minutes for him to settle back down again. "Once you're up, you give a sideways burst to put yourself into orbit and then you're away. There's enough gas in one of these to get you to the next globe, where you can get another one to go further, and some of the globes have prizes on them."

     “Prizes?” said the woman, her eyes shining. “What prizes?”

     “The only way to find out is to go there.”

     "Let me try!" cried the woman eagerly, grabbing a fruit of her own. She aimed the stalk downwards, squeezed it where she'd been shown and with a shriek of delight she shot up into the air. Tak shook his head in amusement and followed her.

     The globe they'd arrived on receded below them, to become just another of the dozens dancing around the sun. Laz turned the fruit sideways and gave another burst, although Tak could see that her first burst had been enough to achieve escape velocity. She was now orbiting not the globe they'd come from but the sun itself. She gave a moan of dismay as she watched it continuing to recede and tried to rectify her mistake by aiming a burst in the opposite direction, but it had no perceptible effect and she cried out in dismay as she aimed one burst after another in every direction, trying in vain to get back to where she'd started.

     "Easy now, easy," said Tak, coming alongside her. "Don't waste gas. The rules here are a little different from what you're used to. I'll teach them to you, but they may take a little time to get used to." As he was speaking she noticed that they were drifting closer to each other, and eventually they came together in a soft and rather pleasant bump. "Gravity's stronger here," he explained as she wrapped her arms around him. "Even our bodies have perceptible gravitational fields."

     "I've always been attracted to you," she murmured happily into his shoulder.

     Tak allowed himself a moment to enjoy the softness of her body against his, then gently disengaged himself from her and held her at arms length. With a gentle shove of his shoulders, he then put them in orbit around each another. "Time for that later," he told her. "Right now, school is in session. Now, the rules are very simple, all you have to do is remember a few simple phrases. Forward is up, up is back, back is down, down is forward..."

☆☆☆

     Thomas awoke with a start, the dream still fresh in his mind.

     Weird, he thought. What a weird dream. People with seemingly godlike powers, able to create whole worlds to be their playgrounds. Quite erotic too. Worryingly so, since the woman in the dream had been Lady Laz, the poor girl they'd rescued from the Southern Continent. Lenny would have some searching questions for him when he told her about it. But why should he have an erotic dream about Connie Laz, whom he'd found only marginally attractive during their time together on the Hummingbird.

     But then, it hadn't been him in the dream, had it? It had been some other guy, someone called Tak, and that was another strange thing. Every other dream he'd ever had, it had been him in it, and so far as he knew it was the same for everyone else as well. He'd never heard of anyone dreaming of being someone else, let alone someone he'd never heard of.

     A shiver of fear ran down his spine. Could it be related to the acquired memories he'd begun to experience aboard the Hummingbird? Could it have been an acquired dream? Some guy called Tak who dreamed of being a godlike being? Someone he'd passed in the street at some point in his life, allowing some of his dreams and memories to leap across? But then why had Lady Laz appeared in the dream? Could Connie Laz possibly have been known to this unknown person Tak as well? He shook his head in bewilderment. This was all way beyond him. He began to think he might need some advice. Professional advice.

     That dream, though. Flying between tiny, overgrown worlds using fruit of compressed gas... What an imagination this guy Tak had! He smiled as he thought of the similarity to their present situation. If only there really was a simple set of rules that would allow them to navigate, to go exactly where they wanted to go. What had they been? Forward is up, up is back...

     He froze. He knew! All of a sudden he just knew, as if the knowledge had just landed in his head like a sack of cement. Of course! That was why they'd ended up so close to where they'd started! it was so obvious! He leapt from his bed and ran back to the bridge to tell Prup Chull that his intuition had been correct.

     Timothy had gone when he arrived, but Prup and Tana Antallan were still there, the moon trog still wearing the Helm of Farsensing that put a dangerous strain on his skinny neck. Hearing the wizard enter, he lifted the visor and stared at him in surprise.

     "How are we doing?" Thomas asked, a silly grin on his face.

     "It is very perplexing," Prup replied with real distress. "You heard me give the order to reduce speed, did you not?"

     "I did," agreed the wizard.

     "Tana here agrees that that is the command I gave, and that that is the command that Rin Wellin gave to the Orb. We did indeed slow down at first, but we are now picking up speed, despite the fact that we have given no other commands to the Orb of Propulsion. The ship is speeding up all by itself. Not only that, but we are also dropping down closer to your world." He shook his head in perplexity. "Maybe we should simply give the reverse instruction to the one we want."

     Thomas's grin broadened. It was the grin of someone who'd looked up the answer in the back of the book while his friends were still racking their brains. "You're very close," he said. "The answer came to me in a dream. Part of me must have been still thinking about it while the rest of me was asleep."

     Tana and Prup stared at him. "It came to you in a dream?" the shae man said. "I have heard stories from among my own people that the answer to a long considered problem can come in a dream, but I have never heard of it happening to a human. It is, so far as I know, unprecedented."

     "Never mind that," snapped the moon trog impatiently. "If you know the answer, tell us! Tell us!"

     Thomas took a moment to savour the moment, then began pacing up and down like a university lecturer. "Our mistake was to forget that everything out there orbits something else. Kronos orbits Tharia, Tharia orbits Tharsol. No matter where we go and what we do, we're always going to be in orbit around something."

     "So?" prompted Prup impatiently.

     "So," continued Thomas, "it's not like we're in a normal sailing boat, sailing between two fixed islands. The islands we're sailing between are themselves moving, just as we are, even when we're anchored alongside one of them. It's... Look, it's..." He faltered, suddenly aware that knowing the answer wasn't the same as being able to explain the answer. "May I borrow your writing pad?”

     Prup fished around in one of his pouches and handed it over, along with a stub of pencil. Thomas drew a rough circle in the middle. “This is Tharia. Right?” The trog and the shae both nodded. Thomas then drew a larger circle around the first. "And this is us in orbit around it. Now, the ship wants to go in a straight line..."

     "Why?" demanded Prup.

     "I don't know, it just does. The ship wants to go in a straight line, but it can't because Tharia's gravity pulls it into a circular orbit, but the faster the ship's going, the straighter it's able to go..."

     "Why?" asked Prup again.
     "I don't know that either. I just know it." In fact, Thomas had the niggling idea that he did know, that the knowledge was there, lying dormant in his head, just waiting for someone to prod it awake. He'd worry about that later, though. Right now he didn't want to be distracted. He drew a third circle. Larger and outside the second except where it touched it at one point. "Anyway, if our orbit curves less, that means we've gone into a higher orbit, like this, and because it's higher that means we're going more slowly, just like you said earlier. So by pushing forward we end up going higher and slower. Do you see?"

     Prup stared at the diagram in furious concentration, his forehead creasing above his watery, slightly bloodshot eyes. "By the Gods," he murmured after a moment. "I think I do see! I think it would be easier to express it in mathematics than words, though." Like Karog, Prup Chull was a student of the church of Calcular, a common interest that had delighted both of them when they'd learned of it, and what was more, the moon trog shared Karog's leaning towards the application heresy. "I can see it in my mind, though, and if I'm right that should be an ellipse, not a circle."

     "You're right!" exclaimed Thomas in delight. "They're all ellipses. I just drew circles to make it simpler." Just a few hours before, Thomas would not have had the slightest idea what an ellipse was, but now a whole multitude of new words were crowded into his mind. Words like parabola. Hyperbola. Escape velocity. Inverse square law. Apothar. Perithar. He worried for a moment where all these new words could have come from, but dismissed the matter with a mental shrug. He must have read them somewhere, that's all.

     "Anyway," he continued, "this is what I think must have happened to us when we left Kronos. We thrusted off towards the ring, which is ahead of Kronos in its orbit, and in so doing we increased our orbital speed. We were indeed going faster at first, but that took us up into a higher orbit, where we slowed down. Then, when we reduced speed, we dropped back into Kronos's orbit and arrived very close to where the ring was when we set off on our journey. While we were moving, though, both Kronos and the ring were moving as well. We ended up right where we wanted to be, but the ring was no longer there. It had moved on, circling Tharia, and Kronos had moved into the space once occupied by the ring.”

     "Yes!" agreed Prup with an almost childlike excitement. "What we should have done was drop down into a lower orbit so that we were moving faster than Kronos. Which is what we're doing now."

     "It's so obvious once it's explained to you. It's only natural that..."

     He was interrupted by a pale, slender hand that gently touched the back of his wrist. "It may be obvious to you, my good friend," the shae man said, looking ashamed and apologetic for his rudeness at breaking in on their conversation. It was a measure of his frustration that he was willing to commit what would have been, in shayen culture, a serious breach of etiquette. "...but I regret that I fail to follow your reasoning. I cannot see how speeding up results in our slowing down. It goes against all the rules of common sense."

     "You're right, it does," agreed the wizard with some sympathy. "So do lots of other things. There are some primitive tribes, for instance, who believe that the world is flat, or that the suns go around Tharia. Both are obvious, of course, when you think about it. Of course the suns go around Tharia! I mean, you see them rising in the east and you see them setting in the west. You see them moving across the sky. It's obvious that Tharia stands still at the centre of the universe and that everything else goes around it. It's obvious, but it's wrong. The truth goes against common sense. Navigation in orbit is just another example. All you have to remember is, if you want to go up, you push yourselves forward. Forward is up. If you want to slow down in your orbit, you go up into a higher orbit. Up is back. Back is down and down is forward. You just aim at ninety degrees to the way you want to go. Call it the ninety degree rule."

     "You might understand better when it's put in strict mathematical terms," agreed Prup, erasing Thomas's diagram and scribbling formulae on the blank pad. "There's no room for misunderstanding there. Numbers never lie."

     "I have no skill with numbers," Tana Antallan said sheepishly. "Few shae folk do. The Gods gave different gifts to each of the four races, it seems."

     "The five races," corrected Prup with a pointed look at the shae man. "We consider ourselves to be a separate race, quite apart from our Tharian cousins. You yourselves resemble them more than I do."

     "I apologise, my good friend," said Tana Antallan, dropping his eyes to the moon trog's feet. "If I caused offence..."

     Prup laughed. "I wasn't offended, my overpolite friend. You shouldn't take everything so personally. We're not made of glass. We won't break if you say the wrong thing."

     "You are more kind than I deserve. I am humbled by your example."

     The moon trog raised his eyes to the ceiling in exasperation. Change the subject, Thomas saw him thinking. "Now that we think we know the rules," he said to the wizard, "why don't we put it to the test? Wouldn't it be great if Saturn comes back aboard to find us moored right alongside the ring!"

     Thomas's grin broadened. "I can't wait to see the look on his face. Let's do it!"

     Prup grinned in reply as he dropped the helm's visor over his eyes, and he began giving instructions to the orbmaster.