The surgery was empty when they arrived, and Anna occupied herself with tidying up while they waited. Gwaine helped, wiping down the tables and sweeping the floor. They had the place practically shining by the time Merlin returned and dropped heavily into a chair. Anna sat down and began cleaning the wound in his leg properly, preparatory to stitching it.

"Merlin," she said at last, keeping her head bent over her work, "what exactly happened last night?"

"I'm not exactly sure," he said slowly.

"But Anna did magic?" Gwaine asked.

"Yes. I just don't know how much. Ouch!"

"Sorry. Just a few more stitches."

"To tell you the truth," Merlin added, gritting his teeth as Anna pulled the wound closed, "last night was a very strange experience."

"You can say that again," Anna muttered, tying off her thread.

"No, I mean—I've never—" He struggled for words. "That's not how magic usually works," he finally concluded.

"What do you mean?" Anna looked up at him for the first time.

"Here." He put his foot down off of the chair and sat forward. "Try to heal the cut on my head."

"Merlin, I—"

"Just try," he said gently.

Pressing her lips together, Anna placed her hand gently over the cut and closed her eyes. "Nothing," she said at last, pulling her hand away.

Merlin caught it. "Try again. You were in a particular emotional state last night—you were desperate; you willed me to be healed. Try to recapture that feeling—that will."

Anna put her hand over it again and closed her eyes. This time when she opened them Merlin and Gwaine saw a flash of golden-yellow light.

"How does it look?" Merlin said to Gwaine.

Gwaine peered at Merlin's forehead. "It's not totally healed, but it's definitely better," he assessed.

Merlin smiled at Anna. "See, I think you have the will, and the instinct to heal, but you just don't have much power."

"Then how did she heal you last night? That would have taken a lot of power, wouldn't it?" Gwaine pointed out.

"Because it wasn't just me," Anna explained. "He was already trying to use his own magic, but he was sick enough that he couldn't. I healed him just enough that he could use his own magic."

But Merlin was frowning. "Isn't that it?" Gwaine asked.

Merlin shook his head. "It makes sense in general. Except—I'm terrible at healing people. Especially myself. I mean, yes, I heal quickly from injuries because I have so much magic, but actually using healing spells on myself—I'm awful at it."

"You've done it before," Anna pointed out. "That time Bergam and Cranog beat you up, you healed your own internal bleeding. I saw you do it—that's how I learned you had magic."

"That seemed strange to me at the time, too," Merlin admitted. "But, since we didn't know you had magic, it seemed like the only explanation—that I healed myself. But if there is another explanation…" He looked up at Anna and put his foot back on the chair. "Try to heal that cut," he instructed.

She shook her head. "It's too deep. There's no way—"

"Just try." He smiled at her reassuringly, and heaving a sigh, she put her hand on it. He covered it with his own, and she stared down at his leg. After a moment her eyes shone golden, and so did Merlin's. When she drew her hand away, she and Gwaine both gasped: though the thread was still in it, Merlin's leg was whole, without so much as a scar.

Merlin was grinning triumphantly. "See? That's what happened! I have plenty of power, but I'm no good at directing it toward healing. You're an instinctive healer. You channeled the raw power and used it to heal me! You must have done it with my internal bleeding, too."

"I remember—I remember a zing, but I thought it was fear," Anna said. "Now that I think about it—it did feel like what happened last night!"

There was a sharp exhalation from the direction of the door, and all three of them jumped and turned. It was only Gaius.

"How long have you been standing there?" Merlin demanded as Anna put a hand over her heart and took a few deep breaths.

"Long enough," Gaius answered. He must have been deeply moved; he didn't even bother to scold them for not being more careful to keep their magic secret. "I've never heard of anything like this," he said, coming forward to examine Merlin's leg. He looked up at Anna. "I've never heard of anyone channeling someone else's magic like this!"

Merlin was grinning. "Think what you could do—what we could do with this!" he said excitedly.

Anna groaned and buried her face in her hands. "But what if I don't want to?" she wailed.

"Anna, magic is part of you—" Merlin began, but Gaius cut him off with a sharp word and a look.

"Anna," Gaius said kindly, putting his hand on her shoulder, "your magic is just that: yours. You don't have to use it if you don't want to—and don't let anyone, not even your friends" (he shot a look at Merlin) "make you if you don't want to. In fact, in the current political situation, I would advise you to use it as little as possible: magic is not safe in Camelot. However," he continued, "I would recommend that you practice, at least a little. It is better to be familiar with your own abilities and how to control them. Otherwise, you are likely to display them involuntarily when you are under great stress, and someone might see."

Anna took a deep breath and straightened her shoulders. "Alright. I'll sleep on it," she said at last.

Merlin was looking thoughtful. "Those aren't the only times you've used your powers," he mused. "There was Gwaine, as well."

"What?" Gwaine said.

"When you were sick," Merlin explained. "I tried to heal you, and nothing happened. But you were so much better the next day—much better than expected. It must have been Anna." He turned back to her. "Remember? You said you were going to pull him through it—that you promised him he'd be alright, and you weren't breaking the promise. That's the will it takes to do the magic."

"But I don't remember actually using any," Anna objected. "Wouldn't I have noticed?"

"Not if the amount of power you were exerting was so small," Gaius answered. "If you exerted a low level of power over a long period of time—say, a few hours—it might not be noticeable except in its effects."

Gwaine was grinning. "I knew it!" He put his hand dramatically over his heart. "You've enchanted me!"

Anna chuckled a little and rolled her eyes. "Well, this enchantress needs a nap. Gaius, can you manage around here without me for a couple of hours?"

"Of course. Get some rest. You too, Merlin," he added, picking up a small pair of scissors and removing the now useless stitches from his leg.

"I'll walk you home," Gwaine offered, jumping to his feet.

"Won't Arthur want you at luncheon to help entertain his guest?"

"Arthur can bear my absence another half an hour," Gwaine answered flippantly and offered her his arm. "Come on, my enchantress."

TBC