A/N: Thank you so much to those of you that reviewed! This is the first fanfic I've ever written that isn't intended primarily as comedy and also the first non-one shot I've done, so I can't tell you how much your encouragement is appreciated. And thank you to those who've put this fic on alert or have favorited it – I'm glad I have you attention =)

Part II : The Blue Spirit

o

Katara enjoyed her day off. Mostly.

It wasn't that having a day to herself where she didn't have baby sit her full grown brother and the almost-full grown savior of mankind wasn't nice, because it most certainly was. She was able to relax without anyone rushing up to her to show her some new trick or whine about needing meat. She could walk around the little market, browsing the shops and stands, without having to say "No, you are not buying that belt, I don't care if it matches the shoes," or "We already have Appa and Momo, we don't need a koala-turtle. Yes, she's very cute, but the answer is still no." She could sit outside of a cute little café, sipping tea and studying a scroll, without being embarrassed by her companions' poor table manners and having to apologize to the owner and other customers before beating a retreat.

Yes, not having to deal with Sokka and Aang for a day was wonderful; their absence was not the problem. The problem was that, well, the people in this town were kind of funny – which was a little ironic considering they seemed to be so insistent that Katara herself was in fact the funny one.

Like the woman at the little jewelry stand that morning.

"What are you reading there, young lady? Must really be something," she had said as Katara walked past, engrossed in the earthbending scroll she had just purchased at the used scroll store a little ways down.

"Oh, this?" she said, a little caught off guard. The woman was probably going to try to sell her something, but Katara tried to be polite and friendly anyway, just as her mother always taught her. "It's just an earthbending scroll… I'm a master waterbender, but my old sifu told me to study the techniques other benders use if I ever have the chance, so I thought –"

"Reading!" interrupted the man at the next stall, a purveyor of fruit. "What's a pretty young thing like you doing reading? Donchya have any friends?"

"I have friends!" Katara insisted, bewildered by his rudeness. "Like I said, I'm a bender, so I'm studying other forms of bending. And anyway I'm not from around here. I'm traveling with my brother and our friend, but I wanted some time to myself, so they went off looking for some ship they heard rumors about, and –"

"Time to yourself? You are the odd one, aren't you," said the woman with a laugh. "It's a good thing you're such a lovely thing. Look at those eyes. Doesn't she have beautiful eyes, Garu?"

"Yes, she does have very nice eyes, I'll give you that," agreed the fruit seller.

Katara didn't quite know how to react to all this and only managed to gape like a half-affronted, half-flattered fish.

"Um, thank you?"

"Oh you're welcome, my dear! Here, why don't you take this bracelet, on the house. It matches your lovely blue eyes."

Katara shook her head at the memory, touching the dyed and beaded leather bracelet now on her right wrist. It was awfully nice of the woman to insist she have it, though of course Katara had offered to pay. She supposed she shouldn't think too unkindly of her, even if she had called her odd.

The girl sighed and stood up from the little table she sat at on the front porch of the inn, looking up at the sky. It was approaching dark, and Sokka and Aang still had not returned. She was beginning to worry and wonder if she should retrieve Appa from the grassy field they had left him in and go searching for the boys.

She was just about to go inside, having decided to give the boys another half hour before she instigated operation "rescue the idiots" when she saw a lone figure dressed in blue running towards her from the path that led into the woods. She stood up, shielding her eyes against the setting sun.

"Sokka…?"

"Katara!" he gasped as he reached her, grabbing her shoulders and breathing hard. "Katara… Aang… blue!"

"Sokka, calm down!" Katara said sitting her brother in the chair she had just occupied. "Take a deep breath and calmly tell me what happened. Where's Aang?"

Sokka leaned forward, gasping for air. He had run without stopping the entire way through the woods and back to the inn and was now on the verge of collapse.

"Something terrible," he finally managed to get out. "That ship, it's haunted. Katara, it has Aang!"

"What has Aang?" Katara asked, feeling her brother's forehead and looking him over for injuries. Then she saw the little trail of blood coming from his clenched right fist. "Sokka, what is this?"

She pried his hand open and found a crumpled rose and stem; Sokka had been clutching it so tightly the thorns cut into his skin. Katara looked back into her brother's face – he didn't seem to even notice that he was bleeding.

"Sokka, you're dehydrated," she told him gently "And your hand… let's go inside so I can heal you and get you some water, and then we'll sit down and figure out what to do."

Half-an-hour later Katara had a watered and healed Sokka sitting in an armchair in the empty common room of the inn. She had pulled up a rickety wooden chair to his side and was now listening in perturbation to his tale. The fire crackled nearby.

"And his teeth – they were more like fangs," Sokka shook his head as if trying to shake the memory out of his mind. "We told him that we hadn't realized it was his ship, that we thought it was abandoned, but…"

"Wait," Katara interrupted, "So this was some kind of spirit?"

"No," Sokka said uncharacteristically grave. "No, it was more like a demon. Aang told it that we had to get back or you'd be worried, and that he had picked the sun rose to give to you…"

Katara looked down at her hands where she cupped the flower. Oh, Aang…

She looked back up to her brother.

"How did you get away?" she asked.

Sokka held her gaze for a moment before turning away and looking into the fire.

"It… he – that thing – when he heard about you…" Sokka took a deep breath a started again.

"I told him about you," Sokka said, a faint edge of regret and guilt to his voice, "Trying to convince him to let us go. I told him how good and kind you are, and how upset you would be if something happened to us. He seemed interested… I thought, I don't know, that maybe he would let us go for your sake, so we could get back to you…"

Sokka was silent for a long moment. Katara looked down at the ruined rose, stroking its soft petals, allowing her brother to take his time and already dreading what his next words would be. Footsteps were heard above them as someone went up the stairs and retired to their room. A door slam, then silence.

"He wants you," Sokka said at last, his voice barely a whisper as the orange glow from the fire danced against his features.

Katara looked up, shocked. She took a moment to process what had just been said.

"He… he wants…?"

Sokka looked at Katara once again, his eyes full of pain.

"He took Aang prisoner and let me go so I could give you the message. He says that if you come to him he'll let the Avatar free." A log shifted in the fire sending up sparks.

After taking a moment to make sure she had heard him right, Katara slumped back and stared blankly ahead. This… demon spirit. It, he, wanted her in exchange for Aang? She could hardly believe any of it. But, she knew her brother well enough to know that everything he had just said was true.

Her life in exchange for the Avatar's. Freedom in exchange for the wellbeing of the world.

It was an easy choice, really. Katara took in a deep breath and sat up and touched her brother's hand

"Do you think you can find the ship again?"

Sokka's brow furrowed in horror.

"What?" he said, yanking his hand away, "No! You are not going Katara. Aang's the Avatar, he can handle himself. I, we can figure out a way around this –"

"Sokka, no," Katara stopped him, her voice firm. "No. It's too big of a risk. Aang isn't fully realized as an Avatar yet and we don't know what this thing will do to him if it doesn't get what it wants."

"We don't know what it'll do to you either. I won' let you–"

"I don't need you to let me!" Katara stood up, the firelight behind her, her silhouette an image of fierce determination. "If you don't show me the way to the ship I'll find it myself. Aang's life is more valuable than mine and you know that, baby sister or not. If I can save him I will, and you will not stop me."

Sokka stared at his sister, and crumpled.

"I'll take you to the ship tomorrow," he said, resignation overwhelming, tears welling up in the back of his throat. "It's too dark out now. I don't think I'd be able to find it without any light."

This was what Katara knew she would hear.

She lowered herself to her knees beside Sokka before placing the flower gently in his hand.

"Thank you."

"I'm so sorry," he breathed. They sat together like that late into the night, as other patrons came and went, until the fire died and they finally went to their separate rooms.

o

The next morning found the siblings trudging along in silence as they retraced the path Sokka and Aang had taken yesterday to the dried inlet. Sokka's eyes were bloodshot; it was evident that he had had little sleep the night before. Katara hadn't fared much better.

The town in which they were staying was a couple hours ride by ostrich horse from the coast, or about an hour's flight by bison; the ship was said to be about halfway between. This meant a good two hours walk to the ship, though with the way Sokka was dragging his feet it would be closer to three. Katara had suggested before they left that maybe they should take Appa, but Sokka insisted that he wouldn't be able to find it again unless they went by land. Katara could see straight through the lie – Sokka had, if nothing else, a sense of direction as sharp as a messenger hawk's – but she let it slide. She couldn't blame him for wanting to stall a fate that she herself was so dreading, though she would never say it out loud.

She tried to remain positive. Sokka wasn't really the best judge of character; maybe the spirit-demon was nicer than he thought. Though holding an innocent boy hostage until his ransom of one young maiden was met certainly didn't seem like the type of thing a nice spirit would do. And why would he rather have her than Aang?

Katara held back a shudder and banished the thought from her mind.

By the time they could see the dried up, scrubby inlet and the ship in the distance the sun was high in the sky. Katara stopped her brother.

"You should stay here. In case it's a trap, so at least someone gets out."

Sokka's jaw tensed.

"Katara, there has to be something else we can do. What will dad say when…"

"He'll say that you did the right thing. That we did the right thing. My life for the Avatar's is more than a fair trade on our end."

Sokka clenched his eyes shut and breathed out hard through his nose before throwing his arms around his baby sister in a fierce hug that lasted only a moment.

"Go," he commanded, turning away, "Quickly."

Katara complied, not wanting to make this any harder than it already was. With one last glance at her brother, she walked the rest of the distance to the ship.

"Hello?" she called when she finally reached it. It was smaller than she imagined somehow. Not that its size wasn't impressive – it was certainly bigger than most water tribe vessels – but it was by no means the largest ship she had never seen.

Hearing no answer and not seeing any other way up Katara used her bending to weave the vines so they could be used as a ladder and climbed up the side of the boat – a technique she had learned when a few members of the Foggy Bottom Swamp Tribe visited the Southern Tribe years ago. She slowly explored the upper deck, senses alert.

"Spirit?" she called, "I'm here for Aang – for the Avatar."

A creak and a thud came from behind her and Katara turned around to see that a hatch leading below deck had opened. She swallowed, noticing suddenly how dry her mouth was. She uncapped her water pouch, despite knowing that it would be of little use against a spirit, and began her descent.

Her way was lit by torches that lined the walls, leading her down stairs and through corridors until far below deck she came to a cell that held a yellow and orange-clad figure.

"Aang?" she breathed, stepping towards him.

He turned towards her voice, and broke into a sad smile.

"Katara," he said. "I knew you'd come. I hoped that you wouldn't, but…"

"Of course I came." She quickly crossed the remaining distance between them and held his hands through bars. "I would never just leave you here knowing I could do something about it."

"I know." Aang squeezed her hand.

"Do you know where the spirit is?" she asked and quickly glanced around the dark room. "Maybe there's a way we can get you out before he even realizes I'm here..."

The lights all flickered out save for one near the cell.

"I'm afraid that will be impossible," came a rasp from the shadows.

Katara turned around with a poorly suppressed gasp, pressing her back to the bars. She peered into the blackness.

"Are you the spirit?"

A large, cloaked figure emerged from dark. She could just make out a shape, the rest in shadow, but she knew from its size that this must be the demon Sokka had spoken of. Katara steeled herself for what she had to do and took a deep breath.

"I am Katara, Master Waterbender of the Southern Tribe," she said in clear voice, not allowing herself to waver. "I am here to offer myself in exchange for the Avatar's freedom."

"I know why you're here," the spirit-demon snarled. He appeared to collect himself before continuing. "You make this offer of you own volition? No one is forcing you?"

Katara glanced at Aang – the boy's head drooped forward, unable to look her in the eye.

"Yes," Katara said, looking back to the shadowed figure. "If you mean that I willingly came here in order to barter for the Avatar's life, than yes, I came here of my own volition. But I can't say that you left me with much choice."

A low growl emitted from the back of the spirit-demon's throat.

"There is always a choice," he said. "Do I have your word that if I let your friend go you will not try to escape?"

Katara didn't hesitate.

"I promise."

The torch flared, revealing a glint of gold beneath the creature's hood.

"Then your offer is accepted. The Avatar is free to go."

Like magic the cell door opened and Aang fell forward into Katara's arms.

"Katara," he said, shaking his head into her shoulder as they hugged, "I can't let you do this…"

"You have to Aang." She pulled back and looked him in the eye. "Your life is more important than mine, you know that."

She felt his frame shudder in a silent sob.

"Tell Sokka I love him, okay?" Katara gave Aang one last hug.

"That's enough!" shouted the spirit-demon. "Take him away."

Shadows appeared out of the air, taking on the rough shape of men, and bodily hauled Aang by the arms and forced him up the stairs towards the deck.

Once the boy was out of sight Katara's strength finally left her and she fell back against the cell bars, clutching them to keep herself upright. Aang was safe, and a weight left her chest only to be replaced by the terror she had refused to allow herself to feel before.

"That's enough," the spirit-demon said roughly. "Stand up."

Katara tried, but she found that her legs trembled too much to hold her entire weight.

"I said stand up!" The spirit-demon pulled her to her feet, and for the first time she could really see him. He wasn't as large as Sokka had described him, but he still loomed over her, easily seven feet tall. His skin was bluer than the robes she wore and he wore no shirt, just a pair of too-short pants and a hooded cloak. His shoulders were broad and his arms thick; the fire light highlighted the contours of every power muscle. He could easily crush the skull of any adversary, if he didn't first tear them open with his long, sharp fangs. And there beneath his scowling brows lay gold eyes, glinting brightly.

Before Katara had time to react to the spirit-demon's terrifying appearance she was being roughly shoved up the stairs, back into daylight.

o

So little sun came in through those narrow windows Katara couldn't tell how long she had been waiting. She could have always gone out onto the deck to check the sun's position – she had been given no order that she must stay in this room, just to make herself comfortable while another was prepared for her.

But Katara, as brave as she was, was still shaken by the sudden turn her life had taken. For the first time since Sokka had appeared yesterday evening she was allowing herself to truly take in everything – the danger her friend had been in, the danger she was in now, the horrible possibilities that awaited her. Spirits were unpredictable and dangerous; not many tales were told of their collisions with the physical world that came to a happy ending for the mortals involved.

No, for the time being, Katara would happily sulk in the relative safety of the room she currently occupied.

Once she had stopped crying for long enough to notice, she found that it was, compared to the rest of the ship, a warm and cheery little space. What sunlight flooded in was supplemented by a little fire that was already roaring when she had stepped in. The floor was swept, the corners clear of cobwebs, and a row of books and scrolls filled the shelf above a desk that hosted ink and parchment.

The girl sat up from the neatly made bed she had been crying on for the past however many hours, rubbing at her eyes, and crossed the room to look again at the titles on the shelf. Several scrolls on Pai Sho strategy, a few dry sounding histories on the Earth Kingdoms and Water Tribes, a well-worn book called The Dao of Tea. She tried to imagine the type of person such a collection would belong to – it certainly didn't sound like the type of reading a demon from the spirit world would be interested in.

Nothing that she found terrible interesting either, if she was honest, though the book on tea did remind her that she was thirsty, probably from all of the crying she'd done. The Spirit had left her with her bending water, but Katara wasn't so parched that she was thinking of resorting to that; even though bending would do little good against a demon, it was comforting to have her element readily accessible at her side, like a security blanket.

She took the book on tea from the shelf and had begun absently thumbing through it when there was a knock at the door, gentle but efficient. Katara didn't move.

"I am sorry to disturb you, young lady," said a kindly a voice through the door, "But your room has been prepared for you, and I thought you might like some nice tea. It will be waiting for you in the next room over when you are ready."

Katara listened silently as the sound of footsteps faded. She looked down at the page the book was open to - a detailed illustration of a steaming cup of tea.

Cautiously, Katara opened the door to the room assigned to her and was surprised by what she saw. A vase of sunny flowers sat on the stand beside her bed, which was made up with a white and blue bedspread. A small hidden window by the bed was un-shuttered, allowing sunlight to stream into the room unhampered by tinted glass. It looked… nice.

A low table sat in the center of the room, set with tea and tea snacks, along with a lit candle. Katara looked around the room, but saw no one.

Remembering her thirst, she sat before the table and took a sip from the tea cup. It was some of the most delicious tea she had ever had, and she took another long drink.

"I hope the tea is brewed to your satisfaction, it has been a while since I've had a chance to test my art."

Katara, startled, looked up and around the room again but saw no one, save for the little man painted in the garden scene on the tea pot. Surely it hadn't been…? But so many strange things had happened… she was, after all, being held captive aboard a haunted ship by a blue demon who was apparently a good enough host to bring her flowers.

Feeling quite foolish, she hesitantly leaned forward and spoke to the pot.

"Did… did you say that?"

A jolly laugh filled the room.

"No, no, that was me," came the voice, this time clearly not from the tea pot but from somewhere across the table, "I am most sorry, but it has been so long since we have had guests, I sometimes forget."

"Forget…?" Katara asked the air.

"I am afraid that to everyone but my nephew I am invisible – just a disembodied voice. I do hope you will accept my apologies for startling you, my dear, it was not my intention."

"Of, of course," Katara stammered out, not sure where or to whom or what she should be directing her forgiveness.

"Please, do not let me keep you from your tea; you must be thirsty." The voice had such a friendly, comforting way about it –like a kindly grandfather – that the girl found herself feeling more at ease despite herself.

"Thank you," she said taking another sip. "The tea, it's very good."

"I am so glad you enjoy it," said the voice, really sounding as if nothing could have pleased him more. "I am afraid my nephew has no appreciation for the fine art of tea brewing. It is nice to have someone who does."

"Your nephew?" Katara put down her cup. "You don't mean that…"

The voice chuckled again.

"Yes, yes, the blue gentleman you met earlier. I am sorry for his behavior – he has never been very good at meeting new people-" at this Katara couldn't help but to raise her eyebrows in disbelief at such an understatement "-but now it seems I am forgetting my manners as well! Allow me to introduce myself; my name is Iroh."

"Oh, I'm Katara of the Southern Water Tribe," she said, beginning to stick out a hand to shake before hastily retracting it and instead settling on a kind of sitting half-bow, half-curtsy. "It's a pleasure to meet you Iroh."

"The pleasure is likewise Lady Katara."

Katara blushed at the formality.

"Well, it's actually Master Katara, but you can just call me Katara."

"Oh, excuse me," the voice apologized. "Of waterbending, I presume?"

Katara nodded.

"Delightful! It has been long since I have had the opportunity to see a master waterbender in action. I hope you will allow me to watch you practice some time."

"Of course," the girl said, smiling into her tea and taking another sip.

"I hope you don't mind me asking," she said hesitantly after a moment, "But have you… well, have you always been like this? Invisible, I mean?"

She heard a great sigh.

"No," the voice said wistfully, "No, I have not always been invisible, although it does feel like it at times. I was once, years ago, just an ordinary man – though even then I believe that most of my acquaintances would have described me as rather eccentric." Another invisible-belly laugh followed this last statement.

"An ordinary man?" the girl repeated, "Then how did you end up like this? How are you related to that thi-your nephew?"

There was a long silence, and Katara feared she may have offended him, or that he had even left.

"I think, my dear, that that is my nephew's story to tell," he said at long last. "I will tell you this, though – my nephew, despite his rather intimidating appearance, does have a good heart. I just hope that one day someone will be able to convince him of this."

A heavy silence settled over the room as Katara took in the voice's words. Curiosity was slowly replacing fear.

"Now, if you will excuse me, Master Katara, I should go find my nephew; I have a feeling he will be in need of my council right about now. Please, make yourself at home. I put some books on the shelf that I thought you might enjoy, and you have your own private bathroom through this door – I am sorry, I forget. I mean to indicate the one opposite the bed."

Katara almost jumped when the candle that sat on the table suddenly floated upwards, stopping in midair.

"If you are ever wondering where I am, just look for this candle. It is my link between this world and that of the spirits' and I must always keep it with me, so there is no need to worry about my lurking about without your knowledge."

Katara began to protest that of course she wouldn't suspect him of doing such a thing, but was cut off by another deep chuckle from Iroh. The candle floated to the doorway and stopped.

"Dinner will be in a few hours; you'll be called for." The candled bobbed forward and down a little – Katara imagined that Iroh must have been bowing – before floating out into the hall, the door shutting behind it.

o

A/N: Reviews and constructive criticism are extremely welcome. Thank you for reading!