Lifting an eyebrow, Merlin feigned puzzlement. "Why would it be impossible? Surely you don't believe Atlantis is the center of the universe, governing the rest of the world in all ways, including customs between men and women? No, Varian, outside this twisted little kingdom of yours is an entirely different world. Serena and I travel together because we wish it. We've been together for years."

"She's your concubine?" Varian demanded hoarsely.

Softly Merlin said, "No. My mate."

Already surprised by the out-of-character way he seemed to be taunting the other wizard, Serena nearly gasped at Merlin's words. She had the odd feeling he meant it, that whatever else he said, that statement was truthful, and she didn't dare look up at him, because she was afraid she wouldn't be able to control her expression.

Luckily, Varian was too shocked himself to notice her wonder. He stood stiffly, staring at them, his armor of arrogance certainly dented-if not split wide open-by this living, breathing impossibility even he, in his wildest sexual fantasies, had seldom considered attainable.

If he had stopped to think at all, he never would have risked himself, but he had the confused impression of a threat they represented to his vision of the world, and it was characteristic of him that he struck out to protect himself, roaring in a kind of dumb animal fury.

The stream of energy that shot from his outstretched hand was white-hot and aimed accurately to strike both Serena and Merlin, a target made easier since they were standing so close to each other. Swifter than thought, both of them lifted a hand, acting instinctively and in concert to block and then repel the destructive energy.

What happened then-should not have. Both Merlin and Varian knew that; Serena had no idea, simply because she had never considered what was likely to happen if the energy stream of two wizards-let alone three-collided, and because she had never been called on to defend herself against another wizard.

What happened was visible to all of them in the heartbeats granted them to ponder. The separate energy streams of Merlin and Serena-his white-hot and hers tinted the searing blue of the base of a flame-met scant inches from their outstretched hands and twined together in an almost sensuous motion, forming a single ropelike shaft of living, writhing power. It sliced through Varian's energy stream like the steel hull of a battleship slicing through water, struck him midchest with an audible craaack, and knocked him thirty feet down the mountain slope.

He picked himself up, panting and shocked, one hand covering the seared place on his chest, and stared at the pair of wizards, who looked gravely back at him. After several silent moments he drew his coat dosed over the burn on his chest, turned, and hurried down the slope away from them.

Serena looked on either side of her and Merlin to find two seared and smoking trees that had taken the brunt of Varian's deflected energy stream, then looked up at Merlin. "What just happened?" she asked hesitantly.

"Positive and negative," Merlin said softly, more to himself than Serena. "That must be it. When they're combined, the energy stream is more powerful… much more powerful." He looked down at her. "Serena, Varian has enough raw power that he should have been able to knock either me or you back a step or two at the very least, but he didn't."

"Because there are two of us?"

"No. If two male wizards had stood here and struck out at Varian, all three would have gotten a nasty jolt that probably would have broken off the attack. And if it had just been him and me fighting through the first jolt even against our instincts for self-preservation, we would have eventually drained each other, possibly to the death. But if we'd chosen to stop it at any point, neither of us would have been permanently damaged or even left physically scarred by the battle. Positive energy, Serena-no matter how many times or ways you combine it, it always cancels itself out."

She frowned up at him. "So what happened with us? Did we knock him off his feet, and obviously hurt him, because we're a pair? Male and female?"

"Positive and negative. And our energy streams were directed together, so they merged."

"You didn't know my energy had a negative charge?" Then she remembered, and answered the question herself. "Of course not, because you've always been so careful that our energy streams never touched during my lessons or whenever one of us was conjuring. Because of the way it always happened with males, you assumed the same danger existed for us."

Merlin nodded. "I should have realized. It explains how male and female wizards are able to harm each other. If it had been just you and Varian here, you in a temper and him scared half out of his wits, both of you could have been badly injured."

"But we weren't alone. You were here. So he got burned-literally-and maybe he'll think twice next time before he barges in on a lady's bath."

With a slight smile Merlin said, "And maybe he'll think about what he's doing here if he knows the outside world is quite a bit different."

Serena looked up at him gravely. "That's why you taunted him? I wondered."

"I shouldn't have done it," he admitted wryly. "I'm not even sure why I did, except… it seemed right, somehow. I seemed to know what I should say to him."

"As if… you'd already said it?"

Merlin frowned a little. "A sense of déjà vu? Yes, as a matter of fact, that was what I felt."

Had he felt that way because what he'd said to Varian was what he was supposed to say? Because their confrontation, like the destruction of this place, had-to Merlin and Serena, anyway-already happened a long time ago?

It had occurred to Serena to wonder if she and Merlin would in some way contribute to the destruction of Atlantis, an unnerving possibility she had promptly put out of her mind. Now it returned, and she had to wonder. Had it been their fate to be a part of the process that destroyed Atlantis? They couldn't be responsible for everything that happened here, Serena knew, because this had been a dying place long before they arrived. But were they perhaps the catalysts, their presence and actions sparking what would become the final upheaval?

Time travel was a tricky thing, its laws elusive and largely theoretical, so how could they know? Perhaps their being here now was a piece of the puzzle, a part of the reason it all happened as it had.

She didn't ask Merlin, because she wasn't at all sure she wanted to hear his answer; sometimes ignorance was indeed a blessed thing. And she didn't ask him something else, though not for the same reason. She didn't ask him why he'd told Varian that she was his mate. Instead she merely suggested that they have breakfast, take another look at the ruins of the Old City, and then head back toward Sanctuary so they could check on the progress of Roxanne and Tremayne.

That was, after all, their best chance at changing the future, which was why they were here.

"Nearly twenty years ago Varian wasn't so careful," Roxanne said with forced composure. "He hadn't yet developed the habit of taking young powerless women up to his palace and keeping them there so he could control his offspring."

Tremayne watched her across the tiny fire. With their late start in leaving Sanctuary, they had gotten less than halfway across the valley before night and the Curtain fell, so they had made camp in the forest. Tremayne had waited until then to ask about her parentage, because he thought she'd be more willing to talk to him with darkness at their backs and the Curtain draining her resistance.

"So Varian… encountered your mother in the village?" he said, keeping his voice neutral.

"No, near the Old City, where she'd gone to pick berries. She didn't fight him, even though she didn't like him at all and was more than a little bit afraid of him. It wouldn't have' done her much good to fight, and in any case, she was like all the village girls: simple and submissive. She just did as he commanded. He told her he'd come back for her later and take her up to his palace, but he didn't. When she realized she was going to bear his child, she had to leave the village, because she knew her father would beat her; the last thing he needed was another mouth to feed. So she went to Sanctuary."