By the condensation jar Snow paused for breath. The woman, he noted, seemed not to need the rest, hardly seemed to be breathing at all. He shook his head and studied the jar. The man was now dead, his body giving up the last of its water for the public good. Snow paused for a moment longer to observe the greasy film on the inside of the jar before moving on. Someone had finished the poor b.a.s.t.a.r.d off.

"Why did you help me?" he asked the woman.

"Because you needed help."

Snow contained his annoyance. With a glance back toward the station he set out again, the woman easily keeping pace with him. She"d had her opportunity to kill him, so it was not the reward she was after. Time enough to find out what her angle was when they had put some distance between themselves and potential pursuit.

Once out of sight of the station they left the road, setting out across a spill of desert to a distant rock field. There, Snow felt, they would be able to lose themselves, unless a sand shark got them first. Hedrew his pistol as he walked and kept his eyes open. One sand shark twitched its motion-detecting palps above the sand, but shortly subsided. It must have fed in the last year; it would be quiescent for another year to come.

Having reached the rocks and firmer ground without event Snow slowed his pace while studying his companion. She was incongruously attractive and clean-looking and he found himself staring in fascination, reluctant to tell her, after what she had done for him, that he normally traveled alone. That, he supposed was the problem-he traveled alone by necessity, not choice. He gave an open-handed gesture and she walked on a pace ahead of him. Whatever danger she represented to him, at least he had her in sight.

Now studying her from the side he said, "I won"t be going much farther. I want to set up camp before the Thira."

The woman nodded, but made no comment.

Snow made a fire from old carapaces and removed his mask in the light of evening. He was curious to note that the woman had not replaced her mask, yet her skin was clear and unblemished. She sank down next to him by the fire, with a grace that could only reflect superb physical condition.

"You never answered my question," he said.

With her head bowed the woman said, "You owe me, perhaps for your life. For that will you allow me to tell you in my own time?"

"People have been trying to kill me. I"m not sure I can afford to be that generous."

She shrugged. "I could have killed you."

Snow bit down on frustration: he did owe her for his life. She could have killed him and, without her help, killers would have gathered at the water station while slow due process brought him to court. He took a deep breath and searched for some stillness.

"What do I call you?" he asked eventually.

"Hirald."

He struggled on, "Where did you come from...before?"

"Across the Thira."

Snow had his doubts about that reply. He had crossed the Thira a couple of times and knew it to be rough going. Hirald looked like someone fresh from a month"s sojourn in a water station.

"I see," he said.

"You are Snow," she said, turning and fixing him with blue eyes that appeared violet in the fading red light.

He felt his stomach lurch at that look, and then he immediately felt self-contempt. After all these years he was still susceptible to physical attraction...to beauty..."Yes, I am."

"I would like to travel with you for a while."

"You know who I am, and I suspect you know why I am suspicious of your motives."

She smiled at him and he felt that lurch again. He turned and spat in the fire.

"I"m crossing the Thira," he said.

"I have no problem with that."

Snow lay back and rested his head on one of the packs. He pulled a thermal sheet across his body and stared up at the sky. The red-tinted swathe of stars was being encroached on by the asteroids of the night-all that remained of Vatch"s moon after some long-ago cataclysm. A single sword of light from an ion drive cut the sunset.

"Why?" he asked.

"Because I"m lonely, and I feel like a change."

Snow grunted and closed his eyes. She was not out to kill him, but her motives remained unrevealed.

Whatever, she could never keep to the pace he set and would soon abandon him, and the unsettling things he was feeling would soon go away. He slept.

Sunlight on his face, bringing the familiar tingling prior to burning, had his hand up and closing hismask across before he was fully awake. He looked at Hirald across the dead ashes of the fire and got the unsettling notion that she had not changed position all night. He sat up, then after a muttered good morning, went behind a rock and urinated into his condenser pack. Following the ritual of every morning for many years now, he then emptied the moisture-collectors of his undersuit into it as well. The collector bottle he emptied into his drinking bottle before dipping his toothbrush and cleaning his teeth. By the time he had finished his ablutions and come out from behind the rock, Hirald had opened a breakfast-soup ration pack and it was bubbling under its lid. Snow reached for another pack, but she held up her hand.

"This is for you. I have already eaten."

"Did you sleep at all?"

"A little. Tell me, how do you come to be in possession of proscribed weaponry?"

"Took it off someone who tried to kill me," he lied. He could hardly tell her he had brought it here before the runcible proscription and modified it himself over many years thereafter. He sat down to drink his breakfast.

When he had finished they set out across the Thira. Hirald noted him looking at her after an hour"s walking and closed her mask. He thought no more of it-lots of people disliked the masks, and were prepared to pay the price of water-loss not to wear them so much.

By midmorning the temperature had reached forty-five degrees and was still rising. A sand shark broke from the surface of a dune and came scuttling after them for a few meters, then halted, panting like a dog, tired or too well fed to continue-that, or it had sampled human flesh before.

When the temperature reached fifty and the cooling units of Snow"s undersuit were laboring under the load, he noted that Hirald still easily matched his pace. When a crab-bird dropped clacking out of the sky at them she brought it down with one shot before Snow could even think of reaching for his weapon, and before he saw what weapon she shot the creature with. She was a remarkable woman.

Shortly after midday Snow called a halt. "We"ll rest until evening, then continue through the night and tomorrow morning. The following night should bring us out the other side."

Hirald nodded in agreement, seemingly unconcerned.

They slept under the reflective shelter of Snow"s day tent, then moved on at sunset after Snow had checked their position. They walked all night and most of the following morning, and when they finally set up the tent again Snow was exhausted. With a hint of irritation he told Hirald he wanted privacy in the tent and suggested she set up her own. Once inside his tent he sealed up and stripped naked. He then cleaned himself and the inside of his undersuit with a cycle sponge-a device that made it possible to stay clean with a quarter liter of water and little spillage. After this he pulled on a pair of toweling shorts and lay back with his miniature air cooler humming away at full power. It was luxury of a kind. After half an hour"s sleep he woke and opened the tent to look outside. Hirald was sitting in the sand with her mask open. She was watching the horizon intently, her stillness quite unnatural.

"Don"t you have a day tent?" Snow asked.

She shook her head.

"Come and join me then," he said, reversing back into his tent. Hirald stood and walked over, apparently unaffected by the baking sun. She entered the tent and closed it behind her, then, after a glance at Snow, she began to remove her survival suit. Snow turned away for a moment, then thought, what the h.e.l.l, and turned back to watch. She had not asked him to turn his head. Under her suit she wore a single, skin-hugging garment. The material was like white silk, and almost translucent. Snow swallowed dryly, then tried to distract himself by wondering about her sanitary arrangements. As she lifted her legs up to remove her trousers from her feet he saw then how the matter was arranged and wondered if a blush was evident on his white skin. The garment was slit from the lower part of her pale pubic hair round to the top crease of her b.u.t.tocks.

As she finally removed her trousers Hirald looked at him and noted the direction of his attention. He raised his gaze and met her eye to eye. She smiled at him and, still smiling, stretched the sleeves of the garment down and off over her hands and rolled it down below her b.r.e.a.s.t.s. Snow cleared his throat and tried to think of something witty to say. She was a succubus, a lonely desert man"s fantasy. Still smilingshe came across the tent on her hands and knees, put her hand against his chest and pushed him back, sat astride him, and with her pale hair falling either side of his head she leaned down and kissed him on the mouth. Her mouth was sweet and warm. Snow was thoroughly aware of her hard little nipples sliding from side to side against his chest. He touched the skin of her shoulders and found it dry and warm. She sat back then and looked down at him for a moment. There was something strange about that look-a kind of cold curiosity. She slid forward onto his stomach, then turned and reached back to pull his shorts down and off his legs. He was amazed at just how far she could twist and bend her body. Once his shorts were removed she slid back until his p.e.n.i.s rested between her b.u.t.tocks, then, after raising herself a little, she continued to push back, bending it over until it hurt, then with a swift movement of her pelvis, took it inside her. Snow groaned, then gritted his teeth as she started to move, still staring down at him with that strange expression.

In the evening, when it was time to go, Snow felt a bone-deep lethargy. He had not slept much during the afternoon. Each time he had tried to relax after a session of s.e.x, Hirald would do something he could not resist. Her last climax had been so intense that she had cried out and shuddered uncontrollably, and after it she had looked down at herself in surprise and shock. Thereafter she had been eager to repeat the experience. Snow felt sore and drained.

As they walked across the darkened violet sands they had talked little, but one conversation had raised Snow"s suspicions.

"Your hand, how did you lose it?"

"Andronache challenge. It was shredded by a flack sh.e.l.l."

"How is it now?"

Snow had paused before replying. Did she know?

"What do you mean: how is it? It was amputated. It is no longer there."

"Yes," she had said, and no more.

The sun was crossing the horizon and the night asteroids fading out of the sky when they reached the rock-field at the edge of the Thira. With little energy for conversation, Snow set up his day tent and collapsed inside, instantly asleep. When he woke in the latter part of the day it was to discover himself undressed under a blanket, with Hirald lying beside him. She was up on her elbow, her head propped on her hand, studying his face. As soon as she saw that he was awake she handed him a carton of mixed juice. He sat up, the blanket sliding down. She was naked. He drank the juice.

"I"m glad you came along," he said, and the rest of the day was spent in pleasant activity.

That night they moved deep into the rock field. The following day pa.s.sed much as the one before.

"I think it fair to tell you I have an implant," Snow said as he rested after some particularly vigorous activity. "You won"t get pregnant by me, and my s.e.m.e.n is little more than water and a few free proteins."

"Why do you feel it necessary to tell me this?" Hirald asked him.

"As you know, there is a reward out for my t.e.s.t.i.c.l.es, stasis preserved. This is not because Merchant Baris particularly wants me dead. I think it is because he is after my genetic tissue. At the water station the Androche...seduced me." Snow was uncomfortable with that. "She did it so she could collect my sperm, probably to sell."

"I know," Hirald said. Snow looked at her and she went on, "He is after your t.e.s.t.i.c.l.es or other body tissue to provide him with an endless supply of your genetic material."

Snow considered that. Of course there had to be more to Hirald than he had supposed, but the s.e.x had clouded his thought-processes somewhat.

"It is the next best thing to having your entire living body. I suspect Baris thought it unlikely he could get away with that. He"d never get your entire body off-planet. This way he also corners the market."

"You know an awful lot about what Baris wants."

Hirald gazed at him very directly. "How is your hand?"

Snow looked down at the stump. He unclipped the covering and pulled it off. What he exposed was recognizably a hand, though deformed and almost useless. The covering had been cleverly made toconceal it, to make it appear as if the hand was missing.

"It will be no different from its predecessor in about six months. I intended to walk out of one water station without a hand, then into another station with a hand and a new ident.i.ty."

"What about your albinism?"

"Skin dye and eye lenses."

"Of course. You cannot take transplants."

"No...I think you should explain yourself."

"The people I work for want the same as Baris: your genome."

"You"ve had opportunity..."

"No, they want the best option, which is you, willingly. I want you to gate back to Earth with me."

"Why?"

"You are regenerative. It is the source of your immortality. We know this now. You have known it for more than a thousand years."

"Still, why?"

"We have managed to keep your secret for the last three hundred years, ever since it was discovered. Ten years ago the knowledge was leaked. Now several organizations know about you, and what you represent: whoever can decode your genome has access to immortality, and through that access to unprecedented wealth and power. That"s why Baris was the first to track you down. There will be others."

"You work for Earth Central."

"Yes."

"Wouldn"t it be better just to kill me and destroy my body?"

"Earth Central does not suppress knowledge." Hirald smiled at him. "You should be old enough to understand the futility of that. It wants the knowledge disseminated so that it doesn"t put power into the hands of the wrong people. It could do immense good. The projections are that in ten years a treatment would become available to make anyone regenerative, within limits."

"Yet prior to this it kept a lid on things," Snow said.

"It guarded your privacy. It did not suppress knowledge. Not to seek out knowledge is not the same as suppressing it."

"Is Earth Central so moral now?" Snow wondered, then could have kicked himself for his stupidity.

Of course Earth Central was. Only human beings and other low-grade sentients could become corrupt, and Earth Central was the most powerful AI in the human Polity. Hirald, noting his discom-fiture, did not answer his question.

"Will you come?" she asked him.

Snow was gazing at the wall of the tent as if he could see through it across the rock field. "This requires thought, not instant decisions. Two days should bring us to my home. I"ll consider it."

Draped in chameleon cloth the hover transport vanished into the surrounding dunes. Inside the transport Jharit shuffled a pack of cards and played a game men like himself had played in similar situations for many centuries. His wife, Jharilla, slept. Trock was cleaning an antique revolver he had picked up at an auction in the last water station. The bullets he had acquired with it were arrayed in neat, soldierly rows on the table before him.

Canard Meck was plugged in, trying to pick up information from the net and the high-speed communications the runcible AI exchanged with its subminds. The call came as a relief to all of them but her-she resented dropping out of that world of perfect logic and pure clarity of thought, back into the sweat-stink of the transport.

"I am Baris," said the smiling face from the screen.

Coming straight to the point Jharit said, "You have the information?"