Both were silent for a few seconds. Finally, Hyatt said, "I don't have time for this, Captain. What is your answer?"

It was then Susan launched her attack. She lunged at him across the desk, grabbing the front of his Survey Service jumpsuit. The fabric tore beneath her prosthetic fingers.

A fraction of a second later, the man in her grasp vanished. Her fingers clutched at empty air.

The door irised opened behind her, and she spun about. Hyatt stepped into the room

"As I said, you can't stop me," the Survey Service Director said. In his left hand he held a blaster pistol he had not possessed only an instant before, pointed at Susan's chest.

"You said a blaster won't work," Susan said.

Hyatt smiled. "One carried across time lines wouldn't. I jumped back only a few minutes, went to the armory and requisitioned a blaster, then returned here. You can't beat me. Eventually you must understand that."

Susan didn't know what to say.

One thing was certain: She could not stop him this way. She knew too little about the pendants and how they worked to put anything together, while he had far more experience with them. The best she could hope for now was a simple escape.

But how could she possibly accomplish even that?

Again, the pendant; it was the only logical answer. She had consciously made it work for her once before, less than half an hour ago, when Lieutenant Krueger had attacked her in her hospital room. Then, she had accomplished it only with considerable difficulty, and Krueger had not possessed a pendant. How might it work against someone who did?

She didn't know, but she had no choice. She knew she must try. It was the only chance she had, and perhaps-just perhaps-she could make it work again.

She could not pull off precisely the same trick. Something as simple as that would not work on this man; he was far too shrewd. Besides, she would have seen herself behind him by now if she was actually going to do it.

But a simple escape…

She focused her thoughts on what she knew must be done. Clearing her mind, she concentrated on-

On what? If she jumped to some time in the past, they would only send someone after her. Someone who would have had considerably more practice with the pendants than she had.

No, she couldn't possibly hide in the past. But what of the future? Might the pendant be capable of projecting her into the future, the same as it had the past?

Of course it could. It had already done exactly that, out on the lunar surface, saving her from dying of suffocation. Or had it?

Not quite, she decided. Then, the pendant had not projected her past a time she had already experienced. What she needed now was to jump to a time beyond any she had yet lived. A time that, in fact, might not yet exist.

But how could she do that? How could she possibly project herself to a time she had never inhabited?

She knew she couldn't accomplish it consciously. Perhaps she could trick her subconscious into performing that feat.

Again she cleared her mind of all thought beyond those necessary to accomplish the task. This time, however, she replaced them with a vague, amorphous thought of the future. It was more a feeling than an actual visualization. After all, this was a future she had absolutely no way of knowing.

Suddenly, she felt the dizziness.

Then, nothing…

The scent of antiseptic nearly overpowered her, and for an instant she thought she was again in the hospital room in Luna City. But that wasn't right. This room lacked corners; every line was strangely curved. There was a no-nonsense efficiency to it, and everything was colored a soft blue.

Before her sat a ridiculously bare control console. And her feet did not touch the ground. She floated in mid-air, and could not tell up from down.

Then it hit her: She was in freefall, onboard a ship. But not just any ship. She was aboard Photon.

And it was no longer on Luna-it was in space!

A woman hung suspended in the acceleration webbing between Susan and the console, her back to Susan. The woman was dressed in a black Base Security jumpsuit, and her dark hair was cropped close to her head.

Before she cleared her throat, forcing that other woman to turn around, Susan knew what she would discover. But still, when she did so, and the woman did turn her head to face Susan, Susan's breath caught in her lungs. The woman strapped into the acceleration webbing before her was Susan herself!

"I've been expecting you," the other said.

"Have you?" Susan didn't know what else to say.

"Of course I have. Think it through."

But Susan couldn't think it through. The headache pounded behind her eyes, draining both her strength and her will. Then the snowflake pattern formed in her thoughts and she mumbled the mantra. The headache became less intense, but did not disappear, and the residual pain was more than it had been last time.

But at least now she could think. And suddenly she knew her duplicate was right. She would be expected. After all, this other had done in her past exactly what Susan was doing now. Her duplicate had the advantage of knowing what would happen, because everything that would happen to Susan had already happened to her. She had come through, solved all the problems. The proof was that she was here, in free-fall, onboard Photon.

Susan kicked off the bulkhead and glided to the webbing. Grabbing it, she steadied herself beside her duplicate.

She couldn't remember ever being so tired. And it wasn't simply physical tiredness-it was a mental exhaustion as well. More had happened to her in the past week that she simply could not comprehend than had occurred in her entire previous life.

Her duplicate seemed to know what she was thinking. "Don't give up now," the other said.

Of course her duplicate knew what she was thinking. After all, this other had once been in the same position Susan was in now. She had thought the same thoughts Susan was thinking.

"Then it will all work out?" Susan asked.

The other shook her head. "I didn't say that. At this very instant, you and I are inhabiting a possible future, but it is only that. Its existence is by no means assured-much might still go wrong."

"What you're saying is, I still might not come through this alive."

"That's right."

Susan fell silent for a few seconds, as did her possible-future self. Finally, she asked, "What do I have to do to make it come out right?"

"I can't tell you that. If I say too much, it won't come out like this."

Susan nodded. She was beginning to understand-some of it.

"What can you tell me?" she asked.

"Only what I was told when I was in your place. Simply this: Part of the answer lies in your past."

"What do you mean?"

"I can say no more."

"But I don't understand…"

"I know." The other smiled. "You'll have to learn to trust yourself, rely on your own instincts. You are the only true ally you have. Remember that. But also remember that you can be your own worst enemy as well."

Again riddles. "Would you just tell me what you mean-what I should do?"

"I can't. I wasn't told, so you can't be. And I felt the same confusion you're feeling now."

Suddenly, Susan knew this other was as trapped by her past as Susan herself was. After all, she was Susan.

Trapped in my past…, she thought, and instantly she knew what she must do. She had just thought it-she was trapped by her past.

The nightmare. The missing occurrences from ten years before. Her duplicate had said the answers were in her past.

Could she jump that far into her past? And could she possibly jump to another star system?

She did not know. She didn't even know if she dared return to that past. If she changed it in any way, everything could be upset. She might conceivably alter her own future.