The storm had blown in in front of the real winter cold. The next morning, it began to snow. By the time Cottia had finished her hour of training with Percival, there was enough snow on the training field that their feet left tracks. She reached down and ran her fingers through the fluffy whiteness.

"It's wet," she said in surprise.

"It is snow," said Percival. "Frozen rain."

"I didn't think it would melt so fast," she said, holding a pinch of snow in the palm of her hand and watching as it melted. She dropped the water and rubbed her hand briskly on her jacket. "That's cold."

She walked back to the castle alone, as usual. The sky was a beautiful shade of grey, and the snowflakes that danced down from the clouds were fascinating to watch. If she stood looking up into the sky, she felt as if she was soaring up to meet the flakes. It made her head spin.

Just under the arch of the courtyard gate, someone bumped roughly into her. "Sorry," she said, stepping out of the way. She caught a brief glimpse of fiery hair and an intense gaze before the person turned sharply and hurried away.

0000

Merlin finished replacing the broken pane of glass in Cottia's room and stood back to look at his work. There had been little breakages all over the castle from the storm the night before. But this one was odd. All the glass had been blown out of the window onto the roof below. Usually most of it landed on the floor beneath the window in the room. He shrugged and turned to leave.

The candle beside her bed caught his eye. It was twisted and melted on top, as if it had been standing in a heavy draft and blazed up. The ceiling above it had faint scorch marks. Merlin went closer and peered at the candle. Something moved under his foot. It was a match. Matches were spilled all over the floor. Out of habit, he gathered them up and placed them neatly back in their box, which was also on the floor. He noticed with a faint sense of uneasiness that there were no burnt match ends among them.

0000

The next day, he took Cottia into the forest with him. It was still snowing, and the horses threw up lumps of snow as they trotted along. Cottia was fascinated by it.

"Everything looks so different," she said. "It's all outlines."

"It's pretty," Merlin agreed.

"I suppose it would be scary to be trapped in a snowstorm, though. The Fellowship was on Caradhras."

"How far have you gotten?" Merlin had been too busy to read to her lately, and she had been left to carry on on her own.

"I just reached Balin's tomb. It's so sad! I liked him. Why did he have to die? And by an ambush, too. It's not fair."

"Life usually isn't fair. People we love die and there is nothing we can do to stop it."

"Gandalf could have saved him if he had been there."

Merlin frowned. "But he couldn't have. Balin had to die. If he hadn't, maybe the Ring would have used him. Maybe the quest would have ended right there."

"Yeah, but Gandalf's a powerful wizard. He can do anything he likes."

"No, he can't. The more power a person has, and the more knowledge of the future, the more badly they can mess it up," he said sadly. "The best thing to do with magic is leave it alone."

"But why? How do you know, anyway?"

"I have seen the most horrible things done by a person who thought they were doing the right thing. They made so many mistakes."

"I hear shouting," said Cottia, looking around. "Do you hear it?"

"What? No." Merlin listened. "Yes. Come on. We'd better -"

An arrow came flying out of the trees and buried itself in the ground under Steady's hooves. He snorted in alarm and reared. Merlin, caught by surprise, lost his balance and fell off his back, landing heavily in the snow.

Cottia slid off Goldberry and ran to him. He was breathing, but limp and unresponsive. "Merlin, come on," she said desperately. The shouting was coming closer. She shook him hard. "Wake up! I think those are - are bad men. We have to leave."

Merlin lay still. She looked up and made a desperate snatch at Goldberry's trailing reins as the horse bolted, followed seconds later by Steady. "Come back!" she shouted furiously. "Cowards!"

Now she could hear branches snapping as the men came closer. She didn't even have her dagger. She looked around for a hiding place, but the snow had flattened all the undergrowth and there was nothing in sight but trees and snow, not even a dip in the ground. It was time for her to run. She looked down at Merlin. A snatch of melody drifted into her thoughts. 'But these battles aside, I think I taught you well.' How could she leave him? 'That we won't run, and we won't run, and we won't run.'

"What's this then?" A group of grubby men appeared from between the trees. And yes, they were all armed. Wonderful. Cottia glared at them, still kneeling beside Merlin.

"Where are you from, boy?"

"Nowhere," she spat. The man looked surprised.

"A girl! Dressed in boy's clothes! What are you, then?"

"I'm his apprentice."

That got a laugh. More men had come up, and now there were about fifteen of them, spreading out to surround her.

"Get up, girl. We won't harm you." There was an unpleasant emphasis on 'you'.

"Why not?" She stayed where she was, shifting back a little so that she was leaning protectively over Merlin.

"We'll get a better price for a pretty girl than an ugly one," the man said, still sniggering.

"What about Me- my master?" Something warned her not to mention names.

"Looks like a weakling. We'll fix that." The man moved closer. He was wearing a jawbone on a chain dangling off his belt, she noticed, and some large and unpleasant-looking keys.

"If you come any closer I will do my best to kill you," she said levelly. The entire group of men laughed this time.

"How, sweetheart?"

"I don't know, but I will try." Curious, she thought dimly. She was so angry for some reason that she wasn't frightened anymore. Just let them touch Merlin and she would - she would do something painful and unpleasant. "I said get back!" she shouted at the man as he reached down to grab her arms.

The man was tossed backwards as if a wind had picked him up. He crashed into a tree and lay mostly still, his arms and legs twitching erratically. Cottia looked around wildly. There was no one in sight but the other bandits. Did I do that? she wondered. I must have. Let's try it again.

She whipped around and glared at a man who was trying to sneak up behind her, and he also went flying before she even had time to open her mouth. Right then, she thought, and then the rest of the men charged her. She sprang up and screamed.

That was something she had never done before in her life. Yes, she'd shouted at things sometimes, in the surprisingly rare moments when she really lost her temper and became seriously and thoroughly enraged, but she had never really screamed for any reason at all. If she was frightened, her natural reaction was to freeze and stare them down. But now, some strange, long-buried instinct told her that screaming was the thing to do at times like this. And it wasn't a frightened, shrill, helpless scream. It was more like a war cry or the howl of wild animals on a scent.

A ring of fire sprang up around her and Merlin, and through the roaring flames she glimpsed another ring around her attackers. She screamed again and they were sent flying, some landing stunned and bleeding and others landing and rolling, scrambling to their feet and slipping in their haste to run away. As suddenly as they had come, the fires went out. Cottia was alone with several very dead bandits and Merlin, unconscious beside her.

Now what? They couldn't stay here. The horses were gone. Cottia thought fast. They had passed a sort of gorge where a big stream ran through the forest about ten minutes before being attacked. They had had to scramble down a high bank to cross the ford. Maybe if she could get Merlin there, she could find a safe place to wait until he woke up. At the very least, she'd have water and it would be out of sight.

She lifted Merlin off the ground and held him somewhat upright, her hands locked around his chest beneath his arms. He was lighter than she had expected, but it was still almost beyond her strength to lift him. She began to drag him back the way they had come.

0000

"Sire!" Sir Percival was running towards Arthur down the long corridor.

"What is it, Percival?"

"Merlin and Cottia's horses have just come back riderless. Something must have happened."

"What? Where were they going?" Arthur began to stride towards the stables. Percival hurried beside him.

"The guards on the town gate say they rode out to the forest. I assume they were going to look for herbs. Cottia sent me a message saying she would be gone all day."

"Has anything been happening in the forest within the last few days?" Arthur's voice was clipped with anxiety.

"Not that I have heard, sire."

"We'd better go anyway. They might be in danger."

0000

Cottia sat on a rock and looked down at Merlin. Her shoulder and ribs were aching horribly. She had thought they were finally healing. But it was worth it, if it meant they were safe. She had carried Merlin all the way to the stream and found a little scooped-out place in the bank, rather like a shallow cave, where she could watch the ford without being seen. It was also out of the snow and sheltered from the wind.

He looks much younger like this, she thought. More relaxed. Less jumpy. She blinked hard. He was still alive. Don't get sappy about it. It's your job to look after him. There's nothing personal about it.

"I wish you'd wake up," she grumbled. "It's freezing out here."

There was a lot of wood lying around on the sandy banks of the stream, and there was a tiny dip in the ground that would make a perfect fireplace. Cottia sat and shivered for a long while before getting up and building a fire. She touched Merlin's hand gently. It was icy.

"I don't have any matches," she said out loud. "Do you?"

She looked through Merlin's pockets, muttering apologetically. He didn't have any, either, or even one of those annoying flint and steel things that she could never get to work.

"Sorry," she said. "It was a good idea, though." She sat and stared at the little pile of kindling. Her candle had lit itself during the storm. She must have done that. She closed her eyes and concentrated on that feeling, that desperate longing for light. There was a crackle and a faint whiff of smoke. A little flame was eating steadily through the kindling.

"Why can I do that?" she asked. "That's never happened before."

As the fire grew, she fed it with some larger sticks. Smoke began to rise and drift along the ground. Merlin stirred and coughed. He rolled over and pushed himself up to a sitting position. "What happened?" He looked around. "Where are we?"

"Back by the stream we crossed. It's the only place to hide that I could see."

"But why are we hiding? What about those noises?"

Cottia shrugged. "I, uh, managed to hide until they left and then came here."

"How many men were there?" Merlin stretched carefully. "Ow."

"You fell off your horse. About fifteen men, I think."

"Who were they?"

"I don't know. Probably slave traders," she added absently, remembering the keys and the remark the leader had made about getting a price for her.

"Really? How do you know?"

"The leader said - " She stopped.

"I thought you said they didn't see you."

She shifted nervously and poked at the fire. "They sort of did," she admitted. "But I . . . I talked them into letting us go." That wasn't really a lie, after all. She had told them she would try to kill them.

Merlin looked skeptical. "Really," he said flatly. "How did you get this fire going? I forgot to bring matches. You don't usually carry them."

"I - I - " Cottia floundered. I can set things on fire by thinking about it? I just killed four or five men by screaming at them? I don't know what is happening to me, but it is very weird and I don't like it at all, but somehow it also feels right?

"Cottia?" Merlin was looking at her worriedly across the fire. "What is it? What did they do to you?"

"Nothing. They didn't get the chance. It just sort of happened. I don't know how. I didn't want to kill them. I mean, I did, but I didn't think it would actually happen," she burst out. Merlin looked even more worried.

"Tell me exactly what happened," he said.

"The men came up, their leader tried to grab me, I shouted at him, and he hit his head on a tree and died, probably, although I didn't check. Should I have? And then another man tried it, and the same thing happened to him. And then all the men ran at me, and I screamed and there was a fire and the ones that weren't probably dead after that ran away." The words spilled out of her. "And during the last storm the candle in my room lighted itself when I thought about light and during the first storm the fire relighted when I couldn't see and just now I thought really hard about wanting a fire and it started on its own."

Merlin came around to sit beside her. He picked up a stick and handed it to her. "Light it," he said.

"What? How?"

"Show me what you did before."

Cottia looked doubtful, but she obediently took the stick and closed her eyes. Merlin watched as a frown of intense concentration grew between her eyebrows. Then her eyes sprang open. The iris glowed golden for an instant. A little tongue of flame sprang up on one end of the stick.

Merlin could not help putting his arm around her and giving her a little hug. "Congratulations," he said gently. "You have magic."

She stared up at him. "What does that mean? Are you sure?"

He took the stick from her and tossed it into the fire. "I'm sure. And I know because - well, watch." He looked at the fire. "Upastige draca," he whispered, reaching out a hand. The flames and sparks formed into the shape of a flying dragon, then dissipated. Cottia stared.

"Your eyes turned golden," she said.

Merlin nodded. "That always happens whenever anyone uses magic. Your eyes did that when you lit the fire just now."

Cottia blinked hard. "I didn't feel anything."

"It doesn't hurt. It just feels . . ."

"Peaceful," she said. "In control."

"Yes."

"Why didn't you tell me that - hey, does this mean you're a wizard? Like Gandalf?" Cottia was looking at him with awe. He blushed.

"Technically, yes, I suppose," he said, running his fingers through his hair. People didn't usually look at him like that. "So are you," he pointed out helpfully.

"Wow. Or like Tiffany," she said happily. "Will I meet fairies now?"

"You might. I don't think you'll like them, though. They're usually rather vicious and self-centered."

She looked disappointed. "I thought you had to be old to be a wizard," she said thoughtfully. "Why aren't you old?"

Because I'm immortal? Merlin thought. Because no matter what I try, this is my permanent form? Oh yes, I can shift into other ones for a while, and that includes looking something like my real age, but I always come back to this, the age I was when I met Arthur and first learned of my destiny? Because I am thousands of years old and spent a lot of that time alone and you are the first person I have ever met with magic who has not immediately tried to kill me? And could you please stop looking at me like that? I'm not a hero. I've done more terrible things and caused more pain and destruction than you could possibly imagine. You're too innocent to stay with me. I have to let you go.

"I'm just a sort of wizard-in-training," he said, managing a smile. Cottia gave him a half-smile, but her eyes were still full of adoration.

"Can you teach me to do that?" she asked, pointing to the fire.

"Yes, and lots of other spells, too. But you will have to be careful. Magic is a dangerous gift. It will get you killed if you use it in public. It could get other people, innocent people, killed even if you manage to avoid being caught."

"Is that why you didn't say anything? Because it's banned? Why didn't you trust me? Does anyone else know?"

"No one else knows that I have magic. And I will never tell anyone that you do too," he added reassuringly.

"But if I keep lighting things on fire by accident -"

"Now that you understand what's happening, you'll be able to control it. Don't worry."

She nodded uneasily. "How long did it take you to find out you had magic?"

"I can't remember when I didn't know. My mother said I could move things around before I could talk. In this world, usually children born with magic are fairly obvious from a very young age. I think something in your world blocks it."

She nodded. "That makes sense. So it runs in families?"

"Yes, always."

"I think it is in my mother's family. They've always been odd."

Merlin got up. "It could. We should look in the records and see if we can trace your family. If your mother's ancestors were druids, it should be recorded somewhere."

"But I thought the whole kingdom was asleep for centuries."

"It was, but not all the people were here. Some of them emigrated to your world before that. Most of them were bands of druids who were fed up with the ban on magic. They've all kept very precise genealogies."

The sound of hooves echoed faintly down the banks of the stream. Merlin kicked sand over the fire as Cottia jumped up. They stood motionless under the overhanging bank.

"Why didn't you run when the men ambushed us?" he whispered after a few seconds. "You didn't know you'd be able to fight them off."

Cottia shrugged. "I was going to," she said. "But then -"

Merlin raised an eyebrow.

"It sounds silly," she muttered.

"What?"

"I thought of that song, you know, the one about the king and the lionheart, and - and - well, you know, 'but these battles aside I think I taught you well'," she said reluctantly. Merlin smiled.

"Really? Thank you."

The horses came closer and splashed down into the shallow water of the ford. It was Arthur and Percival.

"Arthur!" Merlin called.

The King wheeled his horse around and came over to their hiding place. He slid off and ran towards them. "Merlin! We were worried about you! Your horses came back and we thought -" He suddenly threw his arms around his servant. Merlin patted him on the shoulder as he returned the hug, rather startled.

"I'm all right, Arthur," he said. "We were attacked by bandits, but Cottia managed to hide us and they've gone."

"Are you sure?" Percival asked, coming up. He looked worriedly at Cottia. She smiled at him. She liked him. He was honest and unexpectedly intelligent - and he was usefully strong.

"Yeah, they hunted around for a while and then got bored and left," she said.

Arthur finally let go of Merlin. "What happened to you?"

"I fell off my horse. It's nothing."

They rode back to Camelot. Arthur had been in too much of a hurry to bring any extra horses, so he took Merlin up behind him and Cottia rode with Percival.