She had felt it in him tonight, so briefly, when she had reminded him she was no longer a child. And, as usual, she had reacted immediately and out of sheer instinct to right things between them once again. She'd felt driven to retreat, to reclaim childhood or at least a childish mood, to make him forget that he had glimpsed a woman.

The moment always passed, and with it that indefinable tension she felt in him. But more and more, Serena was left frustrated and bewildered, angry at him for some failing she couldn't understand or even describe dearly to herself.

What was it? Was it something in Richard, as she sensed-or something in herself?

In the nine years of her apprenticeship, she had come to know him probably as well as anyone could. Publicly he had been her uncle and guardian; privately he'd been much more. He had been her parent, brother, teacher, companion, her harshest critic, and her best friend.

She had, at sixteen, fallen wildly in love with him. A natural enough thing to happen. That he seemed unaware of her feelings had puzzled her, but she had eventually come to understand that his ignorance stemmed from the same reason he had so instantly accepted a ragged, hungry, rain-soaked sixteen-year-old orphan as his pupil.

Her mind was completely shielded from him.

In time Serena was sincerely grateful for that innate protection. Merlin often knew what she was thinking for the simple reason that she tended to blurt out her thoughts, but he couldn't read her mind. And aside from the benefits of hiding her childish fantasies from him, she also learned to respect the shield itself, for she discovered through Merlin's absent remarks on the subject that few living souls could hide their thoughts and feelings from a Master wizard. It was a sign of great potential power, and not to be taken lightly.

But if her shield hid from him the chaotic emotions he evoked in her, it did nothing to help her cope with them. And because of that failing of his-that lacking, that missing something that made him refuse to see her as a woman-she had the added burden of feeling in limbo, suspended in some bewildering emotional purgatory between woman and child.

So Serena returned to the question once again. How much longer could she go on? The pressure was building inside her; she could feel it. She thought he felt it, too; his occasional business trips out of town had been more frequent with every passing year, and she had to believe the trips had something to do with the increasing tension that lay just under the tranquil surface of their lives.

If he had not been so often remote, especially in recent months, she might have gathered courage and brought up the subject. But he had been.

She couldn't risk it. What she feared most was being sent away, being banished from his life. He was capable of such a merciless act, she thought, given a good enough reason. Though he had never been cruel to her and she had seen no evidence of it, she sensed a streak of ruthlessness in him-perhaps the price he paid for the incredible power he wielded.

Serena was too familiar with the scope of that power to have any wish to put her fete to the test. She wasn't that desperate, not yet. But time was running out. The pressure was building, and something had to give.

Still ignoring the television that was now broadcasting some old movie with melodramatic music, Serena went to one of the windows and stared out. She felt very much alone, and oddly afraid.

It was raining again.

The blinding flash of pink, purple, and blue sparks was wrong, all wrong, and Serena winced even before the deep voice, coming from a dark corner of the room, could reprimand her.

"You aren't concentrating."

"I'm sorry, Master." The proper humility, apology, and respect were present in her voice, but all were belied by the wry amusement shining in her vivid green eyes. In deference to him she was obedient to the longstanding rules governing the behavior of an Apprentice wizard-but only in this workroom. And only when he was teaching her.

From the very beginning she had refused to assume any kind of subservient manner, and Merlin had been wise enough not to insist on many of the ancient and decidedly outdated customs between Master and Apprentice.

"Why aren't you concentrating?" He emerged from the shadows where he'd been observing and stepped into the candlelight, showing her the lean, handsome face and brooding dark eyes of her Master wizard.

"I just have a lot on my mind, I guess. The party last night, for instance," she explained, gesturing idly with one hand and jumping in surprise when a thread of white-hot energy arced from her index ringer to ignite a nearby lampshade.

Merlin hastily waved a hand, and both watched as water appeared out of thin air to douse the tiny fire. The Master turned to his Apprentice in exasperation, and Serena spoke quickly.

"I didn't mean to do it."

"That," Merlin said witheringly, "is the whole point."

Gazing in admiration at the dripping lampshade, Serena ignored the point. "Why won't you teach me to summon water? I can summon fire so easily, it's only logical that I should learn to put out my mistakes."

Ignoring the request, Merlin said, "Stop saying summon, as if the elements are lurking about just waiting to be called to heel."

Serena bunked. "I thought they were."

"I know. But they aren't."

"Then…"

A brief spasm of frustration crossed Merlin's face. "Serena, I can't seem to get it through your head that wizards create. This is what sets us apart from witches, warlocks, sorcerers, and the other practitioners of… magic." The definition was wholly unwilling; Merlin hated putting labels on anything, particularly his art. "We create. We do not need to harness existing elements. We are not limited to that."

"All right. So teach me to create water."

"No."

Serena sighed with regret and unsnapped the Velcro fasteners of her long, black Apprentice's robe. Sweeping it out behind her, she sank down on one of the cushions scattered over the floor and contemplated her jean-dad legs. "I suppose you have a reason?"

Merlin, wearing his midnight blue Master's robe, moved about the dim room, blowing out their working candles and turning on several lamps. Their workroom, tucked up on the third floor underneath the rafters of the house, was always dark owing to the fact that the small, narrow windows were always shuttered. So even though it was the middle of the day, some artificial light was necessary.

The candles were used during work for two simple reasons: they provided a more organic light; and the energy expended during the practice of the wizard's art, particularly when the wizard was an Apprentice and lacked perfect control, tended to cause any nearby light bulbs to burst. In fact, those energies tended to play havoc with anything electrical, which was one of the reasons Merlin had chosen this attic room in which to teach Serena; it was as far as possible from most of the modern appliances in the house.

"Yes," Merlin said in answer to her question. "My reason is a vivid memory of what happened the first time I allowed you to try and create fire."

Her lips twitched, and Serena sent him a look from beneath her lashes. "That was years ago. I was just a rank beginner in those days. And besides, you put the fire out before it could do any serious damage."

"True. However, I doubt my ability to hold back the floodwaters of your enthusiastic creation."

Merlin unfastened his long robe and hung it over a stand in one corner of the room. like Serena, he wore beneath it jeans and a sweater, which revealed a tail, broad-shouldered form that held the considerable strength of well-defined muscles as well as might from less-obvious sources. Serena couldn't help watching him, her expressive eyes still guarded by lowered lashes.