After a moment she said, "But how can we go back into the past of wizards? Won't that affect our present?"

"Not yours or mine, no, at least not directly. I've traced our ancestries back as far as possible, and neither of our personal time lines in any way touches Atlantis."

Serena leaned forward slowly in her chair, reaching out for the edge of the desk as if for support. "Atlantis? The lost continent? That's where we're going?"

"Yes." A frown tugged at his brows, and he said almost to himself, "Still a risk if we change anything, unless there were no survivors. And if there were no survivors, how could what happened there have changed the history of wizards?"

A little numb, she murmured, "Another paradox?"

Merlin stopped scowling and shrugged. "Perhaps. But there must have been survivors. At least one. Someone had to tell the others what happened there. Someone had to know what had gone wrong, or else why would they have felt so strongly that they made the law-and made it so inviolate."

"What law?"

He looked at her for a long moment, then shook his head a little. "The point is that someone must have survived the destruction of Atlantis, and because of that person's beliefs or experiences, a decision was made that altered the society of wizards. That's the only possible answer."

Aware that her question hadn't been answered, but assuming it was because she had strayed into the part of all this he didn't want her to know about, Serena merely said, "Are you sure it was only one person?"

"I'm not sure of anything. My guess is that there couldn't have been more than a few survivors. Atlantis was too remote, and travel too difficult in those days, for it to be very likely that many escaped."

"Surely they had time to plan their escape. Wouldn't there have been some kind of warning? I mean, the whole continent vanished. Even if it sank all at once, wouldn't the people have realized long before it actually happened that they were heading for disaster?"

Merlin shrugged again. "It's difficult to say. I doubt the continent existed in calm for years and then simply disappeared one day; there must have been earthquakes, volcanic activity-something. But that may have been going on for so long that the people simply accepted it as normal. Or they may have been trapped there with no way of escape. Or, even more likely, they may not have realized that their whole world could vanish so completely. Look at the people today who build houses and businesses along earthquake fault lines, Serena; they may know the risks intellectually, but do you honestly think they really face the knowledge that one day it could all be gone?"

"I see what you mean. So the people of Atlantis might have gone blindly to their fate. But at least one escaped."

"I believe that must have happened. Atlantis was so cut off from the other civilizations in the world that no one could have known for certain what happened there unless they were told by a witness."

"Were there a lot of wizards then?" Serena asked curiously.

"More than today-relative to the population at least. And those in Atlantis were probably in some sort of control over their society."

"I thought wizards didn't do that."

"Not now, and not for a long time. But then… who knows? Power has a way of corrupting, and at that time there weren't many other ways to be powerful. There was no worldwide society as there is today, no technology, only crude weapons. Though they were primitive by our standards, wizards must have stood head and shoulders above most others in terms of power."

Thinking of the romantic stories she knew of wizards, Serena said, "How were they primitive? I mean, look at some of the things your namesake did."

Merlin half closed his eyes in a pained expression. "Fiction, Serena. I've told you."

In a small, wistful voice, she said, "No King Arthur?"

He hesitated, then sighed. "I wouldn't go that far. But reality-if it was reality-can never measure up to legend. If there was a Merlin then, and if he was great, it was mostly by comparison to those around rum." Taking note of her dejected air, he decided to abandon the subject of Arthurian legend. "Serena, the wizards of Atlantis are probably first graders in relation to us. They're still learning to read and tell time and count without using their fingers."

She brightened just a bit and, using the same yardstick, said, "If they're first graders, where are you?"

"Working on my doctorate," he said promptly.

She wasn't sure she wanted to hear the answer, but asked anyway. "And me?"

He was silent and reflective long enough to make her nervous, but then said judiciously, "A few credits away from your baccalaureate, I'd say."

Surprised and a bit fluttered, she said, "I thought you'd say I was still in high school."

"You're still a long way from final graduation," he reminded her.

Serena nodded with a stab at meekness, but she was quite pleased by his assessment of her progress. One thing she did know about wizards was that it required a good many years of study to achieve the highest levels of the craft; she had gotten a late start, so if she had done as well as he said, she had every right to be proud of herself.

"In any case," Merlin went on, "we should certainly be able to hold our own with even the most powerful wizard of Atlantis."

Yanked from her self-congratulation, Serena felt a little shiver of unease. "You say that as if you expect us to land in the middle of a battle."

Merlin glanced down at the book before him again, then looked at her seriously. "I don't know what we're going to land in the middle of, but I'm expecting the worst. We should both expect the worst. The continent vanished, Serena; whatever happened there can't be good."

"That makes sense." She took a deep breath. "Okay. So what happens next?"

"First I have to teach you to completely shield your powers. After that I'll build the gate."

Somewhat confused, Serena said, "Shield my powers? You mean, from another wizard? I thought I could already do that."

"No. You shield your thoughts, but the fact that you possess power would be obvious to any other wizard who came near you. I must teach you to project a powerless facade so that no one, not even a Master wizard, will suspect you to be anything other than completely powerless."

"Why?" she asked slowly.

He looked at her for a long moment, as if considering whether to answer her, then said, "I have a hunch that it would be… more difficult for us to travel together if both of us are obvious wizards. But whether I'm right about that or not, it's still a prudent step to take. With your powers hidden from other wizards, we have an ace up our sleeve-and present a less-threatening appearance to those we encounter."

Serena chewed on her bottom lip for a moment, then said, "It won't really affect me, will it? I mean, I'll still be able to use my powers if I need to?"

With that uneasy question, she reassured Merlin that he had made the right decision in electing not to tell her why they had to go back in time. If Serena had any idea that he could steal her powers from her, she would never be able to trust him-and he had a strong feeling her trust was needed.

"Of course you will," he replied calmly. "What I'll teach you to do will be rather like putting on a mask. You'll be able to see and hear clearly, and the mask will remain in place until you reach up and take it off. As long as you wear it, your powers-your true identity- will be hidden behind it. But only hidden. Not changed in any way."

Serena relaxed, not even aware until then that she had tensed. "That doesn't sound so bad. Will it take me long to learn?"

"A few days, I think. And a day at least for me to build the gate. You have a week's vacation left, don't you?"