"Certain. Any security risk would come from your end."

  Renie looked around. There was not a person in sight, but she still leaned close to the screen. "I think I need to get into TreeHouse. Before she died, Susan gave me a message about an old hacker friend of hers—she seemed to think he had some information we could use. His name is Murat Sagar Singh, but he also goes by 'Blue Dog Anchorite.' I think I can find him through TreeHouse."

  "And you wish me to help you get into there?"

  "What else can I do?" A sudden upwelling of pain and anger forced her to measure her words. "I'm just going forward the best I can. I can't think of any other way. I think my brother is as good as dead if I don't get some answers. And now I can't even . . . even. . . ." She took a shaky breath. "I can't even get in to visit him."

  The mystery woman's voice was sympathetic. "Entendu, Renie. I think I can help you to get in."

  "Thank you. Oh, God, thank you." A part of her stood aside, disgusted with such pathetic gratitude. She still had no idea who this faceless woman was, but she was trusting her in a way she had trusted few others. She reached for firmer conversational footing. "Did you find out anything about Atasco?"

  "Not much, I am afraid. He has no involvement that I can discover with the people who own the club you spoke of, Mister J's, or anything else of significance on the net. He seems to keep a low profile."

  Renie shook her head. "So we don't really know whether Atasco or his book have anything to do with anything." !Xabbu had pulled a piece of string from his pocket and constructed a sort of cat's cradle between his outstretched fingers. He was staring at it meditatively.

  "No. We will hope that we can find out something useful from this man Singh. I will see what I can do about getting us into TreeHouse. If I can arrange it, will you be available after work today?"

  Renie remembered the meeting in the Chancellor's office. "I have to do something after class, but I should be finished by 1700 hours, my time."

  "I will call you. And perhaps next time your friend will speak to me." Martine rang off.

  !Xabbu looked up from his string-design to the blank screen, then back down again.

  "Well?" Renie asked. "What did you think?"

  "Renie, you said once you would tell me what a 'ghost' is."

  She closed her pad and turned to face him. "A ghost? You mean the VR kind?"

  "Yes. You once spoke of it, but never explained."

  "Well, it's a rumor—not even that. A myth." She smiled wearily. "Am I still allowed to say that?"

  He nodded. "Of course."

  "Some people have claimed that if you spend enough time on the net, or if you die while you're online. . . ." She frowned. "This sounds very foolish. They say that sometimes people stay on the net. After they're dead."

  "But that is not possible."

  "No, it's not possible. Why do you ask?"

  He moved his fingers, changing the string-shape. "This woman Martine. There is something unusual about her. I thought if a ghost was a kind of strange person on the net, and she was one, then I might understand better. But she is obviously not a dead person."

  "Unusual? What do you mean? Lots of people don't want to show their faces, even if they're not quite as crazy about security as she is."

  "There was . . . something in the sound of her."

  "Her voice? But voices can be distorted—you can't base anything on that. You remember when we went to the club and I made both our voices sound deeper."

  !Xabbu shook his head in mild frustration. "I know, Renie. But something in the way she talked was unusual. And also, the sound of the place where she was. She was in a room with very, very thick walls."

  Renie shrugged. "She might be in some bombproof government building or something—I have no idea what she does besides spook around on the net. God, she had better be legitimate. She's my main hope right now. It might take months to get into TreeHouse on our own. But how can you tell about the walls?"

  "Echoes, sounds. It is hard to explain." He squinted, looking more childlike than ever."When I lived in the desert. I was taught to hear the sounds of birds flying, of game moving across sand many miles away. We listen closely."

  "I don't know anything about her. Maybe she's . . . no, I can't even imagine." She stood up. Down below, she could see students returning to class. "I'll be back in the lab after my meeting. Let me know if you figure anything out."

  Renie barely restrained the impulse to kick the office door off its hinges. As it was, the closing slam blew papers off her desk and almost knocked !Xabbu out of his chair.

  "I can't believe this! They've suspended me!" She was tempted to open the door and thump it closed again, just for something to do with the rage that was running through her like lava.

  "You have lost your job?"

  She brushed past him and flung herself down in her chair, then scrabbled out a cigarette. "Not completely. I'm on salary until my disciplinary hearing. Damn, damn, damn!" She flung the broken cigarette away and seized another. "I can't believe this! Shit! One thing after another!"

  !Xabbu reached out a hand as though to touch her, then pulled it back again.

  Afraid he might lose a finger, she thought. She did feel like biting someone. If Chancellor Bundazi had yelled at her, it would have been bearable, but the look of disappointment had been far more devastating.

  "We've always thought a lot of you, Irene." That slow head-shake, the small diplomatic frown. "I know things have been difficult for you at home, but that's no excuse for this kind of bad judgment."

  "Shit." She'd broken another cigarette. She took a little more care on the next. "It's the equipment I borrowed—I didn't really have permission. And they found out that I fiddled the chancellor's e-mail." She got the cigarette lit and inhaled. Her fingers were still trembling. "And some other things, too. I haven't been very smart, I guess." She was dry-eyed, but she felt like crying. "I can't believe this!" She took a deep breath and tried to calm herself. "Okay, come with me."

  !Xabbu looked bewildered. "Where are we going?"

  "In for a penny, in for a pound. This is my last chance to use the Poly's equipment. We'll see if Martine comes up with anything."

  Yono What-was-his-name was in the Harness Room, oblivious behind his headset as he swayed from side to side, waving his hands and jabbing at invisible objects. Renie leaned hard on the interrupt button. He jerked the helmet off like it had caught fire.

  "Oh, Renie." There was a flicker of guilt in his eyes, evidence of gossip heard and gossip passed. "How are you?"

  "Get out, will you? I need the lab and it's urgent."

  "But. . . ." He smiled crookedly, as though she had made a joke in poor taste. "But I have all this three-double-D work to do. . . ."

  She resisted the urge to scream, but just barely. "Look, I've just been suspended. After this, you won't need to deal with me any more. Now, be a nice man and get the hell out, will you?"

  Yono picked up his belongings in a hurry. The door was closing behind him as Martine's call came in.

  The access path Martine gave them led to an area of the net Renie had never visited, a small commercial node as unlike the mass-market flash of Lambda Mall as a broom closet was to an amusement park. The databank at the end of the French woman's coordinates was of a very basic kind rented out to small businesses, the VR equivalent of the cheap modular storage centers in the real world of Durban Outskirt. The databank's visual representation was as unprepossessingly functional as the unit it represented—a cube whose half-toned walls were covered with buttons and windows which activated and displayed the various services.

  Renie and !Xabbu hung in the center of the cube, their rudimentary sims made even more crude by the node's cut-rate rendering.

  "This looks like the VR equivalent of a dark alley." Renie was in a foul mood. The day had already been hideously long, she had been suspended from her job, and her father had complained when she had phoned to say she'd be home late and he'd have to make h
is own supper—in fact, he had seemed more upset about that than the news about Stephen or her job. "I hope Martine knows what she's doing."

  "Martine also hopes so."

  "Ah. You're here." Renie turned, then stared. "Martine?"

  A glossy blue sphere hung beside them. "It is me. Are you ready to begin?"

  "Yes. But . . . but won't you find it difficult to . . . to work the interface?"

  The blue sphere hung motionless. "It is not necessary to use the virtual interface to get into TreeHouse—it is perhaps easier not to, especially for someone like me who prefers other methods of manipulating data. But since you work with such environments, I thought you would be more comfortable entering it this way. It will certainly make the experience easier to handle when we reach TreeHouse itself, since the VR interface works a little more slowly than other versions. TreeHouse is very fast and confusing."

  Which still doesn't explain why her own sim is so weird-looking, noted Renie. But if she doesn't want to tell me, I suppose that's her business.

  Several of the buttons on the databank interface flared as though they had been pressed, and data began to blur through the windows.

  She's not even using the VR interface, Renie realized. This billiard-ball thing is just a marker, so we'll know she's here with us. She must be doing all this stuff directly from her keys, or offline voice controls, or something. . . .

  "Do you know why this place is called TreeHouse?" Martine asked.

  "I told !Xabbu we should ask you that question. I don't know—logic trees was my guess."

  "It is not so complicated." Martine's laugh was derisive. "It is very simple—they were boys."

  "What? Who were?"

  "The people who first made TreeHouse. Not all were male, of course, but most of them were, and they were making a place that was their very own. Like little boys who build a tree house and have a club and do not let anyone else in. Like the old story of Peter Pan. And do you know how you get into TreeHouse?"

  Renie shook her head.

  "You will appreciate the joke, perhaps. You have to find the Ladder." As she spoke, one of the windows suddenly expanded until it covered an entire wall of the cube."The Ladder can always be lowered," Martine continued, "but the places where it will appear are always different. The people of TreeHouse do not want to encourage people to try to hack their way in. Only those who have climbed the Ladder before know how to find it."

  !Xabbu suddenly broke his silence. "Then you have been to this TreeHouse?"

  "I have, but as a guest. I will tell you more, but now please remember we are in a public place. This is a real databank, but with a connection to the Ladder, or at least that is true today—if you returned to this node tomorrow, I doubt the connection would still be here. But, in any case, someone could come here with legitimate business at any time. Step through."

  "Step through that window?" asked Renie.

  "S'il-vous plaît. Please. There is no danger on the other side."

  Renie moved her sim through the data window. !Xabbu followed her into a virtual space even less detailed than the one they had left, a larger cube of almost pure white. The window irised shut, leaving them alone in the featureless cube: the blue sphere had not accompanied them.

  "Martine!"

  "I am here," said the bodiless voice.

  "But where is your sim?"

  "I do not need any sim here—the bottom rung of the Ladder, like TreeHouse, is beyond the laws of the net. There is no requirement to be embodied."

  Renie. remembered her friend's question about ghosts, and although it was perfectly reasonable that Martine should want to escape one of the petty rules of net life, she still felt a moment of unease. "Do !Xabbu and I need to do anything?"

  "No. I have . . . called in a favor, do you say? I have been allowed back in, and I am privileged to bring guests of my own."

  The white walls abruptly fell away, or rather something different grew out of them. The empty space took on shape and depth. Trees, sky, and earth seemed to form themselves out of invisible atoms in a matter of seconds. Renie and !Xabbu stood before a leaf-scummed pond which was surrounded by a stand of oaks. Martine, if she was still present, was invisible. The sky stretching limitlessly above the branches was summer-blue, and everything was suffused with a warm, buttery light. Near them, reclining between two large roots, his back against a tree trunk and his bare feet dangling in the water, was a small Caucasian boy. He wore overalls, a battered straw hat with a bent brim, and a sleepy, gap-toothed smile.

  "I have permission to visit TreeHouse," Martine said.

  The boy did not seem in the least surprised by the bodiless voice. He squinted at Renie and !Xabbu for a moment, then raised one of his hands in the air, as lazily as if he were reaching to pluck an apple. A rope ladder tumbled down out of the branches above him. His grin widened.

  "Go on," said Martine.

  !Xabbu went first. Renie felt sure he would climb just as deftly in real life. She followed a little more slowly, overwhelmed by the day's experiences and half-fearing whatever might happen next. Within moments the pond and the woods were gone and shadows had pulled in close around her. She was still climbing, but there was nothing to grip beneath her hands, and no feeling that she might fall. She stopped and waited.

  "We have reached TreeHouse," Martine announced. "I am putting us on a private line running parallel to the main sound-line—otherwise it will be very difficult to hear."

  Before Renie could ask what she meant, the darkness abruptly fell away on all sides and the universe seemed to leap into chaos. An earsplitting Babel filled her ears—music, snatches of speech in different languages, odd noises, as though she and her companions were trapped between channels on a short-wave radio. She lowered the overall volume on her system, reducing the noise to a cacophonous murmur.

  !Xabbu's voice came to her clearly on the Frenchwoman's private band. "What sights you have brought to me, Renie. Look!"

  She could not have done anything else. The visual environment that had blasted away the darkness was like nothing she had ever seen.

  There was no up and down—that was the first and most disorienting thing. The virtual structures of TreeHouse connected with each other at every conceivable angle. Neither was there a horizon. The ragged mesh of buildinglike shapes stretched away in all directions. It was, Renie realized, like standing in the imaginary center of an Escher print. She could see empty blue that might be sky peeping from between some of the odd structures, but the color was just as likely to appear below the level of her feet as above her head. In other places, gaps were filled with rain clouds, or swirls of snow. Many of the structures appeared to be virtual dwellings, formed in every conceivable size and shape, towering multicolored skyscrapers crossed like dueling swords, collections of pink bubbles, even a glowing orange mushroom the size of an aircraft hangar, complete with doors and windows. A few of these shifted and changed into something else even as she watched.

  There were people, too, or things that might have been people—it was difficult to tell, since the embodiment codes of the net had apparently been abandoned here—but there were other moving things that barely fit the definition of "object," ripples of color, streaks of interference, whirling galaxies of pulsing spots.

  "It's . . . it's just crazy!" she said. "What is it all?"

  "It is whatever the people who belong here want it to be." Martine's voice, the source of irritation earlier, was now a sublimely familiar thing in a mad place. "They have rejected rules."

  !Xabbu made a startled noise and Renie turned. A floating tugboat covered in leopardskin had suddenly popped into existence beside him. A figure resembling a child's rag doll leaned out of the captain's cabin, examined them for a moment, then shouted something in a language Renie didn't understand. The tugboat vanished.

  "What was that?" Renie asked.

  "I do not know." Her invisible companion sounded dryly amused. "Someone stopping to look at the new arrivals. It is poss
ible to have my system translate the languages spoken here, but it takes a great deal of processing power."

  A high-pitched screaming echoed above the muted babble on the hearplugs, cresting, then dying off. Renie winced. "I . . . how are we going to find anything here? This is insane!"

  "There are ways to operate in TreeHouse, and it is not all like this," Martine assured her. "We will find one of the quieter places—this is public, like a park. Go forward and I will direct you."

  Renie and !Xabbu headed toward one of the gaps between the buildings, rising above a troop of dancing paisley mice, then swerving to avoid contact with something that looked like a huge tongue protruding from the sweating side of one of the structures. At Martine's urging they sped up, and the bizarre tangle of shapes blurred. Despite their rapid progress, some things moved as fast as they did—TreeHouse residents, Renie guessed, coming to take a look at them. These curious folk appeared in such a strange and disturbing assortment of shapes and effects that after a while Renie could no longer bear to look back at them. A burble of sound washed through the gaps between Martine's directions, some of them clearly greetings.

  Renie looked to !Xabbu, worried, but the little man's sim was gazing from side to side like any tourist new to the big city. He did not seem too upset.

  A giant red flower of a sort she did not recognize hung upside down before them, as big as a department store. They slowed at Martine's urging, then rose up into the petals from beneath. As the forest of crimson banners enfolded them, the babble in her hearplugs dropped away.

  Writing flashed in the air before them as they drifted upward, a greeting in several languages. The English section read "This is our property. All who enter remain here under our rules, which are whatever we decide they are at any given time. Most of them have to do with respecting other people. Permission to enter may be revoked without notice. Signed, The Ant Farm Collective."

  "How can you have private property if this is all anarchy?" Renie complained. "Some anarchists!"

  Martine laughed. "You would fit in here very well, Renie. People sit and argue about such things for hours and hours."