Perris Protar clung desperately to the iron handhold, trying with every nerve and muscle to stop his legs from floating out from under him. Damned low gravity! he swore to himself. Places like this should be banned by law! Everywhere should be guaranteed a decent level of gravity, so that ordinary, decent people can get around without having to do acrobatics!

     The moon trog with him chuckled at his obvious discomfort. He was floating serenely a few feet below the ceiling of the huge chamber, needing only to hold onto a thin strand of vine to stop the smallest moon's feeble gravity from pulling him down.

     Except for the central part of the cavern's floor, which had been cleared by the human and moon trog workers who now laboured there, every available rock surface was covered by a layer of vegetation. Walls, floor and ceiling alike, since there wasn't enough gravity to make much of a difference between surfaces of different orientation. The air was damp and humid and a thin film of moisture clung to every available surface. On Tharia, or any decent sized world for that matter, gravity would have pulled the moisture down to form puddles of water in every lowest point, but here the gravity wasn't enough to overcome the water's surface tension, with the result that the life giving liquid spread itself thinly everywhere, so thinly that collecting enough of it to drink was extremely difficult. You could die of thirst here, Perris thought in disgusted amazement. How crazy is it that you can die of thirst in a place damp enough for mosses and ferns to grow?

     The thought prompted him to take a sip from the flexible tube that dangled near his mouth; the tube that was attached to a two gallon tank of water strapped to his back like a diver's air tank. On a planet, gravity dragged the body's water down into the legs and abdomen so that the body's water regulating system, which was located in the head, would make you feel thirsty whenever the amount of water in the head dropped below a certain level. Here, though, on Kronos, where the body's water was free to distribute itself equally all over, that system failed to work properly and a human wouldn't begin to feel thirsty until he was just hours away from death by dehydration. The inhabitants of Kronosia, the moon city, those few who hadn't gone back to Tharia the moment the Beltharans relaxed the restrictions on movement, called it float fever, and the only way of preventing it was to take regular sips of water throughout the day, whether you felt thirsty or not. For Perris, it was just another reason for him to hate the place.

     He and Mong-Tang, the moon trog, hung in silence for a few minutes, watching the hundred or so humans and moon trogs busily at work on the huge object under construction in the centre of the cave. It was a double sphere, one inside the other. Both little more than frameworks of steel and moonmetal at the moment. The outer sphere was twenty five yards across, the inner one twenty yards across. The top half of the inner sphere was empty, a hemisphere of open space, but the lower half was divided into decks and bulkheads. The whole thing sat in a huge cradle, like an egg in an eggcup. Its mass was so great, even at this early stage of its construction, that its own weight was enough to hold it securely in place even in Kronos’s feeble gravity.

     Perris directed the moon trog's attention to the bright flashes of light where other moon trogs were using the ends of optical fibre cables to weld struts and girders to the vast framework. "Are they magical?" he asked. "I thought your people couldn't use magic."

     Mong-Tang laughed. "Indeed we cannot," he agreed. "It is concentrated sunlight."

     "Sunlight?" exclaimed the human in astonishment. "But it's welding metal!"

     "There is no limit to what sunlight can do if you concentrate it enough," the moon trog replied. "Haven't you ever used a lens to burn your name into a piece of wood?"

     "I never even saw a lens until I was twenty five," replied the human thoughtfully. "Then I came into possession of a pair of field binoculars. I dismantled it one day, curious to see how it worked. It was all full of bits of glass. Dozens of them."

     "I expect someone warned you not to look at the sun through it," said the moon trog with a sardonic smile.

     "No," replied Perris with a puzzled frown. "It never occurred to me."

     "Well, try it one day," said Mong-Tang. "Then you'll understand how sunlight can cut metal." He motioned towards the ceiling with an arm as swaddled with layers of clothing as the rest of his body. "Up there, on the surface, we've got mirrored funnels that concentrate sunlight onto the exposed ends of optical fibres. The fibres carry the sunlight to where lenses focus it all into a single fibre, and that fibre carries it here, where we use it. You see that the welders are wearing padded gauntlets? Those fibres are hot. Hot enough to raise blisters on unprotected skin.”

     "Incredible," said the human, genuinely impressed. "It must make a terrible weapon."

     "We moon trogs do not use weapons," replied Mong-Tang. "No matter what kind of weapons we might devise, our physical frailty would make us almost useless as warriors. No, we depend upon the forces of economics to defend us. We supply you humans with treasures that can only be obtained from our alchemists. Glowbottles, optical fibres, firesticks, hardoil, moonmetal. We make it clear that if we are attacked, we will immediately destroy the factories and equipment with which we make these things, thus ensuring that you never again enjoy their benefit. If you want them, you must deal with us as equals, on our terms. Thus it was that the Dallak persuaded your leaders to sign the Treaty of Kronos."

     Perris was delighted to hear the note of contempt in his voice. He was clearly unhappy with the agreement his superiors had reached with the humans. "In which the Beltharans recognise that Kronos belongs to the moon trogs," he said. "Except for everything within Kronosia's gravity sphere, which remains the property of Belthar. A sphere one thousand yards across out of a great ball of rock twenty five miles across. You must be quite pleased with the deal."

     "The Dallak asked for only half of what they could have had," said the moon trog bitterly. "They could have demanded that all humans leave Kronos, that the gravity sphere be dissolved and we take possession of the city. We would have been willing to allow Beltharans to man the observatory, so long as they acknowledged our authority and our ownership of the facility, and they would still have benefited from the materials we would have been supplying them."

     "I can't see the Beltharans accepting such terms," said the human, being careful to let the moon trog see his smile. "The observatory's too important to them. It gives them such an advantage over their enemies on Tharia. They want to make sure they're in control of such an important resource."

     "Our alchemical products are important to them too. Glass ceramic armour, light enough to allow mobility while being impervious to all but the heaviest weapons. Optical fibres for communications. Glowoil for smoke-free indoor illumination. These things give them just as great an advantage, and they don't require a single human to be up here on our world. With that leverage, the Dallak could have forced them to leave Kronos altogether, but instead they settle for a divided moon."

     The deep seated resentment was clear to hear in his voice now. "You humans have vast kingdoms hundreds of miles across. All we have is this one small ball of rock, and we don't even have all of that! You don't belong here. This is our place! The only place where our kind can survive. Look at these." He pushed back the sleeve covering one of his lower arms with the dextrous, grasping hand of the other to reveal the sagging, wrinkled skin covering his puny muscles. "If we went down to your world, the gravity would crush us. You humans can go anywhere, survive anywhere, but we can only survive here. You have so much, we have so little, and yet our leaders still smile happily as you humans take some of what little we have."

     He suddenly remembered who he was talking to and he stared up at the human fearfully, waiting to see how he reacted. "Of course, only the Dallak can see the full picture. No doubt there are other factors that influenced their decision..."

     "No, you're right, it isn't fair," agreed Perris, however, delighted with the way the conversation was going. He'd hardly had to steer the moon trog at all! His outrage at the injustice of the present situation was such that he would probably have ended up making his little speech no matter how the conversation had started. All that remained for him to do now was lead him a little bit further, but carefully! Very carefully!

     "Of course, if you really feel that way, there may be something you can do about it," he said, watching the moon trog cautiously out of the corner of his eye.

     Mong-Tang stared at him suspiciously. "What do you mean?" he asked.

     "Think about it," said the human, leaning over and whispering conspiratorially, even though there was no-one within a hundred yards to hear them. "All traffic between Tharia and Kronos has to go through one little teleportation cubicle. Once, wizards and priests could teleport up here under their own power, but now there's some kind of magical interference that makes that impossible. Even the greatest wizard in the world has to use the teleportation chamber now. Just imagine what would happen if that chamber were somehow put out of action."

     "The humans on Kronos would be stranded up here," said the moon trog thoughtfully. "And those down on Tharia would be unable to help them. Our position would be strengthened enormously."

     "You could negotiate a new treaty with them," said Perris, his eyes narrowing as he watched the moon trog carefully. "Make them acknowledge your authority over all Kronos, including Kronosia, just the way you want it. Most of the original Kronosians have gone back to Tharia. There aren't more than a few hundred humans left up here, excluding the renegades and they're too disorganised to do anything. Your rule would be unchallenged."

     "But the cubicle is right in the centre of Kronosia, right in the middle of the gravity sphere. It would be impossible for us."

     "There may be humans who would be willing to help you."

     Mong-Tang stared at him suspiciously. "Why would humans help us? Why would you betray your own race?"

     "Humans are not all united under a single government," Perris reminded him. "I represent one of the enemies of Belthar. It would be of great benefit to my people if Belthar were cut off from all the benefits of Kronos."

     The moon trog studied him carefully. "If that were true, you'd be placing yourself in great danger by telling me this."

     "The risks are great," agreed the human, "but the potential rewards are great as well, to your people as well as ours, if we can come to an... arrangement. It was no accident that I arranged for us to meet. I've been looking for someone like you for a long time; someone who feels the way you do. We both want the same thing; the Beltharans off Kronos. So, do you want our help or don't you?"

     The moon trog stared at him for a long moment, thinking furiously. "Let us talk about it a little more," he said at last.

     "Of course," replied Perris, turning his head to look at the hard working labourers and to prevent the moon trog from seeing the smile of cruel satisfaction that was spreading across his face.