She found herself looking around for something. Her suit. A deeply ingrained reflex was trying to keep her from stepping into the lock in only her vest and kilt. Those horrible seconds escaping from the Institute came back to her. She repressed the memory. It annoyed her to be prey to unreasoning fears. She knew the null-suit worked; it had come to life a few hours from Jupiter, when the radiation level in the ship had become dangerous.

Sealing herself into the lock as soon as Iphis and Vaffa had gone out, she pressed the cycle button. Goose pimples broke out on her bare skin; then the suit came on and she was fighting for breath. She suppressed the reflex to gasp.

A null-suit was not easy to get used to. Some of it was merely disconcerting, such as finding yourself wrapped in a mirror that followed every curve of your body at a distance of one to one and a half millimeters. When she looked at herself, what she saw was a distorted picture of the things around her, twisted like a funhouse mirror. But some of it was downright alarming. Lilo had been breathing air for fifty-seven years, and suddenly to stop was not easy.

The suit contained a neural link that suppressed the part of the automatic nervous system that controlled her diaphragm. When the suit was on, the breathing reflex was turned off. But it was not quite that simple. Below even the level where digestion, heartbeat, and breathing are controlled was a primitive ape that was just smart enough to realize she was not breathing, but not smart enough to understand the suit was taking care of it. The result was a near-panic reaction.

Lilo knew she could not cope with it. Others had done so; on Mercury and Venus people grew up in null-suits. But for the first five minutes she just held the side of the lock and tried to stop shaking. She found it helpful to think of the process that was keeping her alive. She visualized the irregular metal implant Mari had put in place of her left lung. It contained the nullfield generator, a thirty-hour supply of oxygen, and artificial alveoli that connected with her pulmonary circulation system. The null-suit exchanged oxygen for carbon dioxide, but much more efficiently than her lungs could. The oscillation of her suit's field created a bellows action that forced nearly pure carbon dioxide from the exhaust valve under her collarbone. There were ancillary systems, such as the binaural radio which she could work by subvocalizing in her throat.

She began to feel better. Below her, about five meters down, was the surface, which was a dirty gray color. Some attempt had been made to level it in places, especially the area around the Earthhome's berth. A network of silver ropes stretched between metal supports. It was Poseidon's equivalent of a road system.

Stepping out of the lock had seemed like a good idea, but after a few seconds Lilo saw her mistake. On the way down she had time to calculate the acceleration of gravity, which she found to be almost one centimeter per second squared, or six thousandths of a Lunar gravity. She landed—too hard, with too much reaction—and had time for more calculations as she drifted down again, a little frightened this time. But the escape velocity was quite a bit higher than her legs could deliver. The gravity well was three hundred thirty meters deep, under standard Lunar conditions.

When she approached the surface again she was more careful. She grabbed a rope and pulled herself down. The rope had the same mirror brightness as her body. She watched her silver hands wrap around it, and saw that her suit joined the rope seamlessly as she touched it.

She pulled herself toward the mirror the others had entered. It was another nullfield, protecting the entrance to an underground warren. She tried to go through it, but only got as far as her neck. Vaffa was inside, floating in a bare rock corridor, and she was smiling slightly. Lilo backed out and took off her vest and kilt, which had not been enclosed in her suit when it came on. There had to be a way to get them in, but she couldn't see what it might be. She entered, leaving her clothes behind.

Vaffa was still there, and now she was holding something out to Lilo. It was a pressurized suitcase.

"You'll have to learn about nullfields," Vaffa said. "Nothing gets through them but something that's encased in another nullfield. Except some of them are tuned to let in certain frequencies of light. That's how you can see through your suit."

Lilo was angry, but wasn't going to say anything. She took the box from Vaffa and turned around. The mirror surface was invisible from the inside. She seemed to be looking out the end of an open shaft. As she stepped through, her suit formed around her again.

"Is this some sort of initiation?" she snapped, as she returned with her clothes. Vacuum had not done them any good. The kilt contained volatile plastics which had begun to boil off.

"No," Vaffa said. "Not really. Though it never hurts to get it through your head that things are different here." She paused, and looked at the ruined clothes as Lilo took them out again. "I hope those weren't your favorites or anything."

Lilo said nothing.

"I'll give you a few useful tips," Vaffa said. Lilo looked up, vaguely surprised. Vaffa had never been the type to volunteer anything.

"For free?"

"Sure," she laughed. "One is when you go outside, hold your hair back out of your eyes. The field will compress your hair to your head, tightly, as the air spaces in it are squashed out. If your hair is in your face, you won't be able to see."

"Thanks. I'll remember that."

"The second thing is to be careful when you're talking. That thing in your throat will broadcast whenever you subvocalize. If you think too hard, you might find everyone listening in."

"I'll remember it."

The corridor was round and looked unfinished. Someone had simply bored it out, not bothering about leveling the door. Sprayed stripes of yellow and green indicated the top and bottom, and arrows directed traffic. Lilo knew it would make sense eventually, but her disorientation was nearly total after three turns. Had she gone up or down, left or right? Was the yellow stripe the floor or ceiling? Looking into the rooms that branched off the tunnel every fifty meters was no help; furniture was attached to any convenient surface.

Vaffa took her to a medico's shop. An unsmiling woman sat in a chair behind a desk attached to the rear wall.

"Mari!" Lilo started forward before she recalled. Then she felt the blood rush to her face. Her ears were burning.

"Yes. I understand you knew my clone on Luna," Mari was saying, drifting toward them. "I also know what you did to her."

"I'm... sorry. I—"

"Don't tell me. You didn't do anything. Number three did, I know that, and you're number four. And you didn't do it to me. Nevertheless I think you'll understand if I tell you I don't have much to say to you. Let's get on to business."

Business turned out to be mostly medical. Mari tested her and began a course of treatment that would continue as long as she remained on Poseidon, designed to overcome the effects of weightlessness. Her goal was to keep all the females at the standard point nine-gee muscle-tone level. Mari believed—along with Lilo—that allowing human muscles to adapt to lower gravity states was dangerous in the long run.

Lilo was given a tranquillizer to help her through the disorientation she was feeling, taken to a small cubicle, and told to sleep eight hours, after which she would be briefed on her duties at the station.