Again."

Xiaodan huffed in annoyance at Iroh's barked order and she glared over at him from her bent over position, her hands on her knees as she tried to catch her breath. Zuko stood several feet in front of her in a similar position, his own breathing coming in soft pants. Suddenly the scarred teenage boy straightened and thrusted his fist in Xiaodan's direction, shooting a fire blast at her. Xiaodan yelped and flattened her body against the ground, the fireball passing harmlessly over her.

"Hey!" The white-haired girl shouted angrily as she rolled into a crouch then outstretched her leg and twisted around on her hands, sending a blade of air at the banished prince.

Zuko jumped over the air blade only to be knocked onto his back when another air blast hit him in the chest as soon as his feet touched the ground again. He quickly rolled back to his feet and sent kicked another fire blast at Xiaodan, who nimbly dodged it by twirling to the side. The scarred prince continued sending more fire blasts at the white-haired Airbender, forcing her to go on the defensive as she twisted, twirled, and jumped to evade his attacks.

Iroh watched the two teens critically as they sparred, his darker gold eyes narrowed slightly as Zuko and Xiaodan seemed to dance around each other, either dodging fire blasts or air blades. He stroked his beard lightly and quirked a brow when he saw Xiaodan's molten eyes flash angrily after she had barely dodged a stream of fire his nephew had launched at her.

Xiaodan turned her head and stared wide-eyed at the tree that had been blackened by the stream of fire she had barely managed to dodge. Her eyes narrowed and she slowly turned her head to stare at Zuko, who was smirking cockily at her as he stood in a Firebending stance. Without thinking, the white-haired Airbender ran at Zuko, surprising him with her forward attack, though he was quick to recover and he began shooting fireballs at her from his fists, which she lithely dodged as she ran at him.

Xiaodan used Airbending to propel herself up into the air and somersaulted over the scarred prince, who spun around to face her. Xiaodan landed in a crouch just in time for the blast of fire Zuko had shot at her to fly over her head harmlessly. Without straightening from her crouch, Xiaodan pushed her hands against Zuko's stomach, sending him sprawling several feet away with a powerful air blast to his gut.

Zuko growled as he pushed himself to his feet and he prepared to attack the smug looking white-haired girl but his uncle stepped between them with his arms outstretched towards them.

"Enough." Iroh stated firmly, looking sternly first at his nephew then the female Airbender, "We'll end training is over for today and call it a draw."

"Finally!" Xiaodan exclaimed and allowed herself to collapse on her back then she raised head slightly to make a face at Iroh, "And I totally won that spar, Iroh."

Iroh chuckled lowly and shook his head in amusement as he set about preparing a pot of tea. Zuko scowled at his uncle then he crossed his arms and turned his scowl on the white-haired girl. Xiaodan merely smiled cheekily at him and let her head fall back onto the ground.

"What's out here?" Sokka asked in confusion as he stood with his sister and Toph and stared at Aang, who was sitting cross-legged on the ground.

"A lot actually." Toph replied as she kneeled and put her hand on the ground, "There's hundreds of little-"

"Shh!" Aang cut Toph off quickly as he turned to look at his three friends, "I know you can see underground but don't ruin the surprise. Just watch."

The young Avatar held the flute he was holding to his mouth and blew a single note, a second later a groundhog-like creature popped out of a hole in the ground and mimicked the note.

"Yeah!" Aang cheered with a laugh then played another note and another singing groundhog popped up and mimicked the note, "I'm putting an orchestra together!"

"An orchestra, huh?" Sokka asked sarcastically then waved his hands slightly, "Well, la-di-da..."

Three groundhogs suddenly popped out of different holes and sang three descending notes right after the other. Momo chittered and dove at one of the groundhogs just as all three of then disappeared into their holes again, the lemur following after them, only to pop out of a different hole.

Aang played four more notes, a groundhog mimicking each note right after he played it while Momo tried to catch any singing groundhogs that popped up, causing Katara to giggle with amusement. Aang played another note which was cut off abruptly when Sokka stomped over to him and plugged the flute with his finger.

"This is great and all, but don't we have more important things to worry about?" Sokka demanded in annoyance as he straightened while Aang moved the flute away from his mouth, "We should be making plans!"

"We did make plans." Toph replied matter-of-factly as she stood beside Katara, "We're all picking mini-vacations."

"There's no time for vacations." Sokka snapped exasperatedly and Aang looked up at him with a small pout.

"I'm learning the elements as fast as I can." Aang whined slightly, "I practice hard every day with Toph and Katara. I've been training my arrow off!"

"Yeah," Katara piped in as she walked over to stand beside Aang, "What's wrong with having a little fun in our down time?"

"Even if you master all of the elements, then what? It's not like we have a map of the Fire Nation." Sokka grumbled then gestured to the side as he continued sarcastically, "Should we just head west until we reach the Fire Lord's house?"

He pretended to knock on an imaginary door, "Knock, knock. Hello, Fire Lord? Anybody home? I don't think so. We need some intelligence if we're going to win this war!"

Aang waited for Sokka to finish his rant then he played another note on the flute and a groundhog popped up underneath Sokka, mimicking the note before disappearing back into its hole when Momo tried to catch it. Katara giggled slightly and Aang Airbended himself to his feet.

"Alright," She conceded as she placed her hands on her hips, "We'll finish our vacations and then we'll look for Sokka's intelligence."

Aang laughed at her joke then went to get his map from Appa's saddle. After he had jumped back to the ground he opened the map and showed it to Katara.

"Your turn, Katara." Aang said with a grin as Katara leaned forward to get a better look at the map, "Where would you like to go on your mini-vacation?"

"How about the Misty Palms Oasis?" The dark-haired girl questioned as she pointed at the map, "That sounds refreshing."

"Oh, yeah, I've been there with Xia." Aang stated with a nod of his head as he looked at the spot on the map then back at Katara, "It's a pristine natural ice spring. And I usually don't use the word 'pristine.' It's one of nature's wonders."

Aang, Katara, and Sokka stared at what used to be the oasis with disappointed expressions while Toph gazed blankly forward, her expression just as disappointed with what she was able to sense.

"Must've changed ownership since Xia and I were here." Aang said with a sheepish laugh as he walked past the gates.

Sokka and Katara exchanging unamused looks before they along with Toph, followed the young Airbender. The sign hanging from the entrance suddenly fell down and shattered, causing the four to turn and look at it warily.

Aang cleared his throat awkwardly and continued walking further into the oasis, his friends following him. They walked past the small, remaining ice spring, where a dog was licking ice eagerly towards the bar where five men wrapped in cloth were standing. Aang, Toph, and Katara walked past the men and into the bar, but before Sokka could enter the establishment, one of the men spat at his feet. Sokka glared at the man angrily and the man gave a rasp groan and wiped his mouth with a slurp then he chuckled darkly at the Water Tribe boy. Katara exited the bar and grabbed her brother, pulling him into the building which was filled with weary travelers and shady characters.

"One mango, please." A man said to the bartender.

The bartender pulled two swords from his back and used them to slice a bowl from a chunk of ice on the counter then he cut some mangos from the fruit hanging above him then he began dicing them up. The four friends stared in surprise as he picked up the pulpy remains of the fruit and dropped it into the ice bowl then he used his swords to pick up a jug off the counter and pour the liquid into the ice bowl with the fruit pulp. The bartender tossed a bamboo straw into the bowl along with a decorative umbrella then he gave it to the man, who tossed a coin onto the counter.

"I don't see anything wrong with having one of those fruity beverages while we plan our strategy." Sokka stated with a grin then he pushed past his friends and ran up to the bar, "Excuse me."

Aang, Katara, and Toph followed him at a slower pace, the man from before turning around just as Aang reached them. The man accidently bumped into Aang, spilling his drink all over his front.

Aang looked down at his clothes then smiled up at the man, "No worries, I clean easy."

The man gasped when Aang Airbended the drink off his clothes.

"You're a living relic!" The man stated in awe as he looked at Aang with wide eyes.

"Thanks, I try." Aang replied with a shrug,

"An Air Nomad, right in front of me." The man stated with admiration as he cupped his chin then be bowed briefly Aang, "Professor Zei, head of anthropology at Ba Sing Se University."

Aang bowed to the man in returned then blinked in surprise when Zei grabbed his arm and began inspecting the arrow tattoo on his hand.

"Tell me, which of the air temples do you hail from?"

"The Southern Temple." Aang replied, giving Zei a strange look when the professor began measuring his head with a compass.

"Oh, splendid!" Zei exclaimed happily, "Now tell me-what was the primary agricultural product of your people?"

"Uh..." Aang said in confusion, "Are fruit pies an agricultural product?"

"Oh, truly fascinating." Zei muttered as he stepped away from Aang and pulled a journal from his pack, "That is one for the journal."

"So Professor," Sokka addressed Zei as he wrote in his journal, "You're obviously a well-traveled guy. Do you have a more current map? Ours seems to be a little dated."

"Certainly." Zei replied and he rummaged in his pack for a moment then he handed a rolled up scroll to Sokka.

Sokka walked over to a vacant table and unrolled it while Aang, Katara, and Zei stood around him with Toph sitting down across from him, her feet propped up on the table and her drink in hand.

"What, no Fire Nation?" Sokka asked in exasperation as he stared at the map, "Doesn't anybody have a good map of that place?"

Katara furrowed her brow slightly as she examined the map over her brother's arm, "You've made a lot of trips into the desert."

"All in vain, I'm afraid." Zei replied with a sigh, "I've found lost civilizations all over the Earth Kingdom, but I haven't managed to find the crown jewel, Wan Shi Tong's library."

"You spent years walking through a desert to find some guy's library?" Toph asked in disbelief as she shifted slightly in her chair.

"This library is more valuable than gold, little lady." Zei chided lightly, causing Toph to not -so subtly roll her eyes, "It is said to contain a vast collection of knowledge, and knowledge is priceless."

"Hmm... sounds like good times." Toph muttered sarcastically and took a sip of her drink.

"Oh, it is." Zei responded, oblivious to the blind girl's sarcasm, "According to the legend, it was built by the great Knowledge Spirit, Wan Shi Tong, with the help of his foxy knowledge seekers."

"Oh, so this spirit has attractive assistants, huh?" Sokka asked interestedly, a sly smirk on his face.

Katara put her hand on her brother's face and pushed his head slightly to keep him from talking any more.

"I think he means they look like actual foxes, Sokka." The dark-haired girl stated drily as she stared sternly at her brother.

"You're both right. Handsome little creatures." Zei said with a happy expression then he pulled out a scroll with a drawing of the library on it and he put it on the table, "Wan Shi Tong and his knowledge seekers collected books from all over the world, and put them on display for mankind to read, so that we may better ourselves."

Sokka looked at the drawing then addressed the professor, "If this place has books from all over the world, so you think they've got info on the Fire Nation? A map, maybe?"

"I wouldn't know." Zei responded with vague sadness in his tone, "But if such a thing exists, it's in Wan Shi Tong's library."

"Then it's settled. Aang, I do believe it's my turn. I'd like to spend my vacation..." Sokka said then he pointed at the ceiling and his tone became dramatic, "at the library!"

"Uh, hey, what about me?" Toph demanded from her seat, "When do I get to pick?"

"You gotta work here a little longer before you qualify for vacation time." Sokka replied matter-of-factly as he crossed his arms over his chest.

"Hmph!" Toph scoffed in annoyance and slammed her drink on the table then crossed her arms.

"Of course, there's the matter of finding it." Zei mused as he rubbed his chin slightly, "I've made several trips into the Si Wong Desert and almost died each time. I'm afraid that desert's impossible to cross."

Sokka frowned slightly then his expression brightened as he got an idea.

"Professor, would you like to see our sky bison?"

"A sky bison?!" Zei exclaimed in shock and excitement, "You actually have one?"

Sokka nodded then led the group outside where Appa was recoiling from four of the men wrapped in cloth, growling lowly at them.

"Sandbenders, shoo!" Zei barked as he ran towards the four men and waved his arms at them, "Away from the bison!"

The four Sandbenders hurried away and got into two sand-sailers, driving them away by creating a small tornado of sand near the sail, leaving Zei and the four teens alone with the calmed sky bison.

Katara and Toph leaned against opposite sides of the saddle as Appa flew across the sky over the desert while Sokka sat near the front of the saddle, tying his shirt around his head before grabbed a telescope and looking over the side of the saddle with it. Aang sat on with Professor Zei and Momo on Appa's head, the young Airbender holding the reins as he peered around curiously. Zei suddenly crawled forward slightly and leaned over Appa's head to stare down at the sky bison's face.

"Tell me, sky bison, are you the last of your breed?" Zei asked curiously and Appa growled in response, prompting Zei to reply enthusiastically, "Delightful! I only wish I spoke his head."

"Oh, the stories this beast could tell." The professor commented as he scratched Appa's head as Momo crawled up to his side and started chittering at him, "Shush, chatty monkey."

Momo gave an annoyed chitter and shuffled back over to Aang, who was examining the picture of the massive library.

"Wow," The young Avatar muttered, "Shouldn't be too hard to find a place like this out here."

Appa continued flying over the desert, the sun beating down on the five and Zei moved to sit in the saddle with Katara, Sokka, and Toph.

"Does this place even exist?" Toph asked with a frustrated groan as she slumped against the saddle edge.

"Some say it doesn't." Zei replied cheerily.

Toph's blind eyes widened in surprise then narrowed in irritation.

"Shouldn't you have mentioned that before?" She demanded then collapsed on the saddle, her feet hanging over the side.

What felt like hours later, Appa was still soaring across the sky and the five had gradually become more discouraged. Zei was writing in his journal while Sokka, Katara, and Aang were looking for the library and Toph leaned against the side of the saddle.

"There it is!" Toph shouted suddenly and pointed in a random direction , causing the other four to look in the direction she was pointing.

They're faces fell when all they saw was sand dunes and they all turned to look at Toph with annoyed expressions on their faces.

"That's what it will sound like when one of you spots it." Toph quipped drily and waved her hand in front of her face, a sarcastic grin on her face.

Appa continued flying while Sokka and Katara returned to spots at the front of Appa's saddle, searching for the library on either side while Aang directed Appa with Momo sleeping on his head.

"It shouldn't be this hard to spot a giant, ornate building from the air." Katara said exasperatedly as she shaded her eyes with her hand.

Sokka glanced at her then looked through his telescope, spotting a down in the distance.

"Down there," He called out as he pointed in the direction of the tower, "What's that?"

Momo jerked away with a chatter when Aang moved his head to look in the direction Sokka was pointing, his hand coming up to shade his eyes from the sun. When Aang spotted the tower, he quickly directed Appa down towards it. Appa circled the tower a few time before landed on the ground, sending up a small cloud of sand around his feet. The five quickly jumped from Appa's back and head and walked closer to the tower.

"Forget it." Katara said with a sigh as she held up the picture of the library and looked up at the tower, "It's obviously not what we're looking for. The building in this drawing is enormous."

A sudden sparkle in the distant catches the group's attention and they all stared in surprise as a foxlike creature holding a scroll in its mouth walked over a dune then ran towards the tower.

"What kind of animal is that?" Sokka questioned curiously as the fox-creature ran up the tower and crawled through a window at the top of the tower.

"I think that was one of the Knowledge Seekers." Zei said in awe as he looked up at the window where the fox-creature had disappeared in, "Oh, we must be close to the library!"

Sokka furrowed his brow and peered at the picture Katara was holding then he looked back at the tower.

"No, this is the library-look!" He said as pointed at the tower in the picture then at the tower in front of them, "It's completely buried.

"The library is buried?" Zei cried out dramatically as he ran forward, waving his hands around wildly then he collapsed to his knees, "My life's ambition is now full of sand."

The four teens watched as he suddenly perked up and pulled a small shovel out of his robes.

"Well, time to start excavating."

Toph rolled her eyes and walked towards the tower then she slammed her hand against it.

"Actually, that won't be necessary." The blind Earthbender commented idly, "The inside seems ot be completely intact. And it's huge."

"That foxy thing went in through the window." Sokka said as he cupped his chin and looked up at the windows at the top of the tower, "I say we climb up there and give it a look."

"I say you guys go ahead without me." Toph replied and Katara put her hands on her hips.

"You got something against libraries?"

"I've held books before." Toph responded with a bored shrug, "And I gotta tell you, they don't exactly do it for me."

"Oh, right." Katara said sheepishly when she was reminded that Toph was blind, "Sorry."

Toph smiled good-naturedly at her then gestured towards her ear, "Let me know if they have something you can listen to."

Xiaodan closed her eyes and evened out her breathing as she attempted to mediate, something she was finding surprisingly difficult at the moment. She just couldn't seem to empty her mind, her thoughts racing around what had transpired between her and Zuko a few days ago, atop the hill during the storm. Xiaodan had no idea what had possessed her to hug him, other than the fact that he looked so broken and sorrowful in that moment that she just had to comfort him. The utterly defeated look hadn't belonged on his usually proud, scowling face. Both had silently decided not to speak of that incident again.

Huffing to herself in annoyed manner, Xiaodan let herself flop backwards onto the ground, temporarily giving up on trying to meditate and she just let her thoughts wander as they pleased. She closed her eyes and wondered what her brother and friends were doing right now, if Aang had begun learning how to Earthbend, how was his teaching coming along, were Toph and Katara getting along, her thoughts about her friends seemed endless as they flitted about her mind. Suddenly her thoughts veered in a completely different direction and she began thinking about the vision she had in the Foggy Swamp and why Zuko had appeared in her vision.

"I thought you were meditating."

Xiaodan cracked her eyes open and gave an exasperated groan when she saw the object of her current musings standing above her with his arms crossed over his chest as he vaguely glared down at her.

"I am meditating and you're distracting me. Go away." The white-haired girl retorted then closed her eyes, "Ohm."

Zuko quirked a brow and stared down at the girl strangely as she continued to pretend to meditate. His brow rose higher when she opened one of her eyes again, his expression silently asking if she was stupid or something. She opened her other eye and sat up with a sigh, folding her hands demurely in her lap.

"Did you actually need something, Firebug, or are you just gonna stare at me?"

The banished prince scoffed and looked off to the side, ignoring the heat he could feel creeping along his cheeks as he crossed his arms even tighter across his chest. He had wanted to ask the girl why she had comforted him that day he had tried to get lightning to strike him, but his pride prevented him from doing so and he quickly said the first thing that came to mind.

"Uncle sent me to tell you that the tea is ready."

"Oh, well why didn't you just say so?" Xiaodan exclaimed as she Airbended herself to her feet and strolled in the direction of the camp they had made earlier.

Zuko rolled his eyes upward, as if asking the universe why he had to deal with the strange female Airbender before he let his arms fall to his sides and he followed her back to the camp where his uncle was waiting for them. He just hoped she didn't realize his uncle hadn'tsent him to get her.

Sokka finished tying the rope to his boomerang then he tossed the weapon into the window, giving it a quick tug to make sure it would hold then he began scaling the side of the tower.

Aang watched Sokka scale the tower, followed by Katara and Professor Zei then he turned towards Appa.

"Don't worry, buddy, I'm not making you go underground every again. You can stay out here with Toph."

Aang patted his nose once then walked over to the tower to follow his friends and the professor. Appa gave a low, rumbling growl and Toph turned her head towards him, her arms crossed over her chest.

"What's up?" The blind girl asked awkwardly.

"Oh, it's breathtaking!" Professor Zei gasped as he looked around the vast library as he and the three teens climbed down the rope while Momo flew down, "The spirit spared no expense in designing this place. Look at those beautiful buttresses!"

Sokka and Aang giggled, causing Zei to look at them in confused curiosity.

"What's so funny?"

"Nothing." Aang replied quickly as he tried to smother his grin, "We just like architecture."

"As do I." Zei said obliviously as he reached the bottom of the robe and stood on a bridge, the three teens following him a moment later while Momo landed on Aang's shoulder.

"My word!" The professor gasped as he pushed his hat back and examined an owl mosaic above two pillars, "The exquisite mosaic handiwork of this tile-rendered avian symbol..."

He trailed off when he caught the quizzical looks Sokka, Katara, and Aang were giving him and he chuckled nervously then pointed towards the mosaic.

"Eh, nice bird?"

A sudden rustling noise came from behind them, causing Sokka and Katara to run behind a pillar while Aang grabbed the professor and dragged him behind the pillar opposite the two siblings. The rustling continued and Aang craned his neck so he could peer around the pillar, his eyes widening slightly when he saw a massive black owl standing on the bridge, examining the rope they had used to get into the buried library. The owl spirit turned around, revealing white spots that looked like eyes on the back of his head, which suddenly turned nearly all the way around.

"I know you're back there..." The owl spirit commented coolly.

Aang gasped quietly and ducked his head back behind the pillar, pressing his body against the column firmly. The professor suddenly smiled and walked out from behind the pillar, Aang lifting his hand to grab him but Zei had already moved back onto the bridge.

"Hello, I'm Professor Zei, head of anthropology at Ba Sing Se University." The professor introduced himself as he approached the Wan Shi Tong.

"You should leave the way you came." Wan Shi Tong stated coldly then glanced to the side where three stuffed animal heads were hanging on another pillar, "Unless you want to become a stuffed head of anthropology."

The professor gulped and rubbed at his neck nervously as he stared at the stuffed head. Katara, Sokka, and Aang walked out from behind the pillars they had been hiding behind and headed towards the owl spirit and Professor Zei.

"Are you the spirit who brought this library to the physical world?" Sokka asked quickly.

"Indeed, I am Wan Shi Tong, 'He Who Knows Ten Thousand Things.'" The owl spirit drawled emotionlessly, "And you are obviously humans, which, by the way are no longer permitted in my study."

"What do you have against humans?" Aang questioned curiously, his head tilted to the side slightly in confusion.

"Hm! Humans only bother to learn things to get the edge on other humans." Wan Shi Tong rumbled in annoyance as his thoughts drifted to another man that had come into his library many years ago, "Like that Firebender who came to this place a few years ago, looking to destroy his enemy."

"So..." The owl spirit all but hisses as he leaned towards Sokka, who had started sweating slightly, "Who are you trying to destroy?"

"What?" Sokka squeaked, gulping as he stared nervously at his reflection in the owl spirit's solid black eyes, "No-no-no-no destroying. We're not into that."

Wan Shi Tong blinked slowly, "Then why have you come here?"

"Um..." Sokka faltered then smiled apprehensively as the owl spirit leaned closer to him, "Knowledge for knowledge's sake?"

"If you're going to lie to an all-knowing spirit being, you should at least put some effort into it..."

"I'm not lying," Sokka protested then grabbed Aang and pushed him towards Wan Shi Tong, "I'm with the Avatar and he's the bridge between our worlds. He'll vouch for me."

"Ow!" Aang grunted quietly when Sokka nudged him in the ribs with his elbow then he looked up at the owl spirit, "Uh, yeah, I'll vouch. We will not abuse the knowledge in your library, good spirit. You have my word."

The four bowed to the knowledge spirit, who stared at them emotionlessly for a moment before speaking.

"Hmm... very well. I'll let you peruse my vast collection on one condition," Wan Shi Tong conceded, watching as their hopeful expressions became slightly worried, "To prove your worth as scholars, you have to contribute some worthwhile knowledge."

Professor Zei walked forward and kneeled before the owl spirit, holding out a book, "Please accept this tome as a donation to your library."

"First edition, very nice." Wan Shi Tong commented then swiped the book from the professor's hands with his wing.

"I have an authentic Waterbending scroll." Katara stated, holding out the unrolled scroll for the spirit's inspection.

"Ooh, these illustrations are quite stylish." He said then grabbed the scroll with his wing, Katara smiling slightly as she backed away.

"Uh...oh, I know!" Aang stammered then his expression brightened and he began rummaging around his shirt until he pulled out his wanted poster then he showed the owl spirit, "Hah!"

If he had eyebrows, Wan Shi Tong would have raised them as he took the wanted poster, "I suppose that counts."

"Oh, great spirit," Sokka said dramatically as he walked forward, a piece of string in his hand, "Check this out!"

The Water Tribe boy quickly tied the string into a butterfly knot then presented it to the owl spirit.

"Ta-da!" Sokka exclaimed proudly and Wan Shi Tong looked at him in silence, "It's a special knot. That counts as knowledge!"

"You're not very bright, are you?" The owl spirit asked rhetorically then swiped the knot from Sokka's hand, "Enjoy the library."

Sokka scowled angrily as the owl jumped off the bridge and flew down to the lower levels of the library then the young warrior turned and followed his sister, Aang, and the professor towards the rows of books.

"Bright enough to fool you." Sokka muttered with narrowed eyes.

Toph sat cross-legged beside Appa in the shade of the tower, her elbow resting on her knee while she cupped her chin.

"So...you like...flying?" Toph asked the bison awkwardly and Appa purred deeply then scratched his ear.

"Of course, I'm more comfortable on the ground where I can see. Well, I don't see the way you do. I feel the vibrations in the ground with my feet." Toph continued idly then she picked up a handful of sand and let it fall through her fingers, "But this sand is so loose and shifty, it makes every look fuzzy."

Appa gave a rumbling groan in response.

"Not that there's anything wrong with fuzzy." Toph said hurriedly and the sky bison grunted once in reply.

Aang leaned against one of the many bookshelves in the library, watching in awe as a Knowledge Seeker deposited a scroll on the shelf he was leaning against then he turned back to the book in his hands while Sokka, Katara, and Professor Zei browsed the bookshelves around him. The young Airbender flipped the page of his book and he grinned.

"Hey, look at these weird lion turtles." Aang called out as he held up the book to show Sokka and Katara the illustration of a man talking to a lion-turtle with two other lion-turtles in the background.

"Eh, I've seen weirder." Sokka said dismissively as he pulled a book off the shelf and stuck it in his bag after looking at it for a moment.

"Aang," Katara stated as she walked over to the Airbender, holding a book in her hands, "Did you know in a past life, you were left-handed?"

Aang grinned and rubbed the back of his head, "I always knew I was special."

Sokka rolled his eyes slightly and peered up at the massive bookshelves on either side of him, walking past Professor Zei, who was adding books to the large stack already in his arms. The Water Tribe boy took a scroll from one of the shelves and opened it slightly then placed it in his bag with a grin. Sokka's brows furrowed curiously when he caught sight of a podium standing near the back of row of bookshelves and he walked over to it curiously.

"'The darkest day in Fire Nation history.'" He muttered aloud as he read the burnt piece of parchment framed on the podium, "It's got a date at the top, but it doesn't say anything else."

Sokka looked around quickly then unsheathed his machete and pried open the frame with it, taking the parchment from it. He looked it over one more time then quickly rolled it up and turned around just as Aang, Katara, and Professor Zei walked out from between two bookshelves.

"Sokka, where are you going?" Aang asked curiously as Sokka ran down a section of the library.

"I want to know what happened to the Fire Nation on their darkest day. This could be promising." Sokka replied as he continued running through the library, the other three following him.

"The information on the Fire Nation should be right up here." Sokka stated as the four walked down towards an open door with the symbol for right above it.

The four entered the room and stared in shock and horror at the massive pile of ashes.

"Firebenders." Aang said softly.

"They destroyed everything having to do with the Fire Nation." Katara murmured in shock as she looked at all the ashes.

"That's so unfair! Just when I think I'm one step ahead of the Fire Nation, it turns out they beat us here a long time ago." Sokka shouted angrily as he stepped further into the ash-filled room then collapsed to his knees, "I need to know what happened on the darkest day."

A sudden whimpering caused the four to turn around and look at the entrance, where a Knowledge Seeker was standing on its hind legs.

"Hello, weird little fox guy." Sokka said warily as they approached the spirit creature.

The Knowledge Seeker dropped down onto all fours and turned around, pointing outside the room with its nose.

"Seems it's trying to assist you." Professor Zei observed curiously.

"Um, sure, I guess I'll follow you." Sokka muttered and began following the fox creature, Aang, Katara, and the professor trailing after them.

The Knowledge Seeker led the foursome towards a large round down with a texture lining the bottom sides of the wall. The spirit creature disappeared into a small door in the texture and the large, round door suddenly slid open, revealing the Knowledge Seeker standing behind it. Aang, Katara, and Sokka glanced at each other briefly then entered the room with Professor Zei. The four walked towards calendar wheel in the center of the room and the Knowledge Seeker pushed a lever beside the calendar wheel, causing the domed ceiling to suddenly change from day to night.

"This room is a true marvel, a mechanical wonder!" Professor Zei gasped as he looked up at the domed ceiling where stars were glowing faintly, "It's a planetarium that shows the heavens moving!"

The domed ceiling changed back to day, lighting up the room as a moving metal beam with an image of the sun passed across the blue of the sky.

"Uh, this is beautiful, but how is it helpful?" Sokka asked aloud as he scratched his head in confusion.

"Maybe these dials represent dates and times." Katara suggested as she looked at the calendar wheel, "Sokka, try entering that date from that parchment you took."

"Shh, Katara!" Sokka stage-whispered at his sister and he glance at the Knowledge Seeker, "Not in front of the fox, he's with the owl."

The Knowledge Seeker whimpered sadly and ducked its head while Sokka tried to surreptitiously glance at the burnt parchment then he began changing the four wheels of the calendar to the right date then he pushed the lever. The domed ceiling changed from day to night again.

"Wow, I got to hand it to you, Sokka." Aang commented as he looked up at the planetarium in awe, "You picked the best mini-vacation for sure."

The ceiling continued to change, shifting from night to day and suddenly the planetarium went dark.

"Hey, wait." Katara said in confusion, "What happened to the sun?"

Aang narrowed his eyes and glanced at Sokka, "Great, you must have broken it."

"It's not broken." Sokka stated as he walked up beside Aang and looked at the moon piece of the planetarium was covering the sun piece, "The sun is behind the moon. It's a solar eclipse! It's literally the darkest day in Fire Nation history! Now I get it!"

Sokka grabbed Aang by the shoulders and shook him, "Something awful happened on that day. I don't know what, but I do know why. Firebenders lose their bending during a solar eclipse!"

The Water Tribe boy suddenly pushed Aang back, causing him to stumble slightly.

"Sorry." Sokka apologized sheepishly and Aang just waved his hand dismissively.

"That makes sense." Katara commented as she walked up to her brother and Aang, "I mean, think of what the lunar eclipse at the North Pole did to the Waterbenders. This is huge!"

The Knowledge Seeker suddenly got on its hind legs and whimpered pleadingly at Sokka.

"Fine, you've earned it." Sokka said with a grin as he tossed the fox a strip of dried meat from his bag and the fox caught it eagerly in its mouth then trotted away.

"We've gotta get this information to the Earth King at Ba Sing Se." Sokka continued, addressing Katara and Aang, "We'll wait for the next eclipse, then we'll invade the Fire Nation when they're totally helpless. The Fire Lord is going down!"

"Mortals are so predictable, and such terrible liars."

Sokka gulped and turned around slowly, his eyes widening when he saw Wan Shi Tong standing in the entrance to the planetarium.

"You betrayed my trust." Wan Shi Tong all but growled, "From the beginning, you intended to misuse this knowledge for evil purposes."

"You don't understand." Sokka protested desperately as he tried to explain to the angry spirit, "If anyone's evil, it's the Fire Nation. You saw what they did to your library. They're destructive and dangerous. We need this information."

"You think you're the first person to believe their war was justified?" The owl spirit demanded harshly, "Countless others before you have come here seeking weapons or weaknesses or battle strategies."

"We had no choice." Aang pleaded with the spirit to understand, "Please, we're just desperate to protect the people we love!"

"And now I'm going to protect what I love." Wan Shi Tong snapped and began to violently flap his wings.

"What are you doing?" Aang asked panicked as the room began to shake violently.

"I'm taking my knowledge back." The knowledge spirit responded coldly, "No one will ever abuse it again."

"He's sinking the building!" Katara gasped as sand began pouring from the ceiling, "We've gotta get out of here!"

"I'm afraid I can't allow that." Wan Shi Tong stated, not sounding regretfully at all as his neck lengthened dramatically, "You already know too much."

The owl spirit suddenly pecked at them but the four managed to scramble away just in time to avoid the blow and they quickly ran from the room, heading towards the rope that would help them escape. Wan Shi Tong pursued the four as they ran out of the planetarium, his elongated neck stretching towards them.

Appa lifted his head and snarled when he saw the tower was sinking further into the sand.

"I already told you, I don't want to snuggle." Toph said in exasperation then yelped when Appa stood and hurried towards the tower, causing her to fall onto her back, "Library's sinking."

Her eyes widening and she ran towards the sinking tower, "Library's sinking!"

Toph punched both fists into the wall of the tower to stop of from sinking further, but her feet slipped in the sand and she paused briefly to solidify it.

"Hi-yah!" The blind Earthbender grunted as she punched her fist into the tower wall again, struggling to stop it from sinking any further.

Katara, Sokka, Aang with Momo on his shoulder, and Zei ran through the library, rounding a corner sharply while Wan Shi Tong continued his aggressive pursuit, his wings destroying the bookshelves he flew past.

Professor Zei suddenly stopped running and turned to face the angry spirit, his voice pleading, "Great Knowledge Spirit, I beg you, do not destroy your vast collection of priceless tomes!"

Wan Shi ignored him and flew straight at him. Aang stopped and spun around, using Airbending to create move the professor out of Wan Shi Tong's attack and over to where Katara and Sokka were standing then Aang quickly fired an air blast at the owl spirit, knocking him off the side of the bridge they were standing on.

"We've gotta get back to the surface!" Aang exclaimed as he ran back to Katara, Sokka, and Professor Zei and the three began running down an aisle, while Sokka remained where he was.

Katara stopped and looked at her brother urgently, "Sokka, let's go!"

"But we still don't know when the next eclipse is gonna happen!"

"Don't be stupid!" Katara snapped at her brother, "We'll find out later."

"No, we won't." Sokka stated firmly, "If we leave this place, we'll never get the information. Aang, come with me to the planetarium, I need cover."

Aang ran up to him and Sokka handed Katara Momo.

"Katara, take Momo and get out of here." The Water Tribe boy ordered then he and Aang turned to run back to the planetarium.

"But...!" Katara started to protest but Wan Shi Tong suddenly broke in between the two groups.

"Go!" Sokka shouted urgently and Katara and Zei began running as Wan Shi Tong pursued them.

"Hurry Sokka!" Katara yelled over her shoulder as she ran away from the furious owl spirit.

Aang and Sokka watched worriedly as Katara with Momo run away from Wan Shi Tong then the two boys quickly ran back in the direction of the planetarium.

Professor Zei ran after the young Water Tribe girl then dove between two bookshelves, the angry owl spirit flying past him and after Katara. The professor lifted his head and his eyes brightened with excitement as he pulled a book from one of the shelves and looked at the cover excitedly.

Meanwhile, Katara ran between the shelves then she glanced over her shoulder when Momo chittered a warning in her ear, her eyes widening when she saw Wan Shi Tong swooping towards her.

Appa grunted nervously as Toph continued to struggle with holding the library up.

"What is it now?" The blind Earthbender asked through clenched teeth as she turned her head to look over her shoulder.

Suddenly, three sand-sailers were racing towards them and Appa roared angrily when he was suddenly struck by a blast of sand.

"Who's there?" Toph demanded angrily as her eyes narrowed.

Appa growled lowly as the sand-sailers began to circle around him and one of the Sandbenders jumped off one of the sailers then headed towards Appa.

"Why are we doing this?" Aang asked as he followed Sokka into the planetarium.

"Because if this calendar can tell us about eclipses in the past, then maybe it can project when the next one will be." Sokka replied as he stopped in front of the calendar wheel.

"You can't possibly check every single date!" Aang stated in exasperation as he moved to stand by the lever.

"I don't have to." Sokka said as he began adjusting the calendar wheel, "We just need to check every date before Sozin's Comet arrives. Because after that-well, try not to think about that."

Sokka finished adjusting the wheels and Aang pushed the lever, causing the dome ceiling to begin to change. Sokka changed the date on the wheel again and Aang pushed the lever, the dome changing again but not landing on the eclipse. The two continued to change the date and push the lever, hoping each time that it would land on the solar eclipse.

"C'mon, eclipse!" Aang said urgently as he pushed the lever again and the moon and sun began traveling across the domed ceiling until the moon overlapped the sun and came to a stop.

"That's it! The solar eclipse! It's just a few months away." Sokka said ecstatically and he quickly took out a piece of paper and wrote down the date then he shoved it back into his bag, "Got it. Now, let's get to Ba Sing Se!"

The two boys ran out of the planetarium hurriedly, hoping that they were either meet Katara on the way to the rope or that she was already there.

Appa roared loudly as the Sandbenders surrounded him and began tossing weighted ropes over his body. The bison roared again and reared onto his back legs, causing the Sandbenders to solidify the sand around their feet in order to bring Appa down.

"Don't make me put this down!" Toph screamed then she let the sinking library go and Earthbended a slice of sand at the Sandbenders, but missed because she couldn't 'see' them and she quickly turned back around, slamming her fists into the tower wall again.

Appa growled as his legs were knocked out from under him and he was tied up more firmly by the Sandbenders then they began dragging him away from Toph.

"No! Stop sinking!" Toph shouted at the sinking building then she spun around and Earthbended three more slices of sands at the already leaving Sandbenders.

"No!" Toph shouted and grabbed the library again, bowing her head and closing her eyes sadly, "I'm sorry, Appa."

Appa groaned quietly and let his own eyes slide partially shut as the Sandbenders dragged him away.

Katara panted quickly as she ducked beside a bookshelf and clutched Momo to her chest while Wan Shi Tong walked on the other side of the book shelf. The knowledge spirit's eyes suddenly narrowed in on the lemur's striped tail peeking out from behind the bookshelf.

"At least I'll have one specimen to add to my collection." Wan Shi Tong commented as he lunged forward and tried to grab Momo with his beak, but Katara managed to run away with Momo clutched in her arms.

The dark-haired Waterbender panted as ran across the bridge towards the rope then she spun around to face Wan Shi Tong once she reached the rope, shifting into a bending stance with Momo perched fearfully on her shoulder.

"You're Waterbending won't do you much good here." Wan Shi Tong stated as he unfurled his wings to attack, "I've studied Northern water style, Southern water style, even Foggy Swamp style."

Aang suddenly flew over the owl spirit on his glider with Sokka holding onto him. Sokka let for with a yell, holding a book high above his head, which he slammed onto Wan Shi Tong's head, knocking him unconscious.

"That's called Sokka style." Sokka crowed with a laugh, "Learn it!"

Katara and Sokka quickly climbed over the unconscious spirit's neck and they began climbing up the rope while Aang flew around them on his glider.

"Wait!" Sokka shouted suddenly when he realized they were missing someone, "Professor, let's go!"

"I'm not leaving." Professor Zei said as he sat among a pile of books, a scroll in his hands, "I can't. I've spent too long trying to find this place. There's not another collection of knowledge like this one earth. I could spend an eternity in here."

"Just go!" Katara shouted at her brother just as Wan Shi Tong came too.

The angry owl spirit screeched and grabbed the rope with his beak, shaking it roughly and causing Katara and Sokka to fall off it. Aang gave a wordless shout as he swooped down and caught them then he flew up towards the opening, Wan Shi Tong hot on their trail.

Aang, Katara, and Sokka flew out of the tower window, the Water Tribe siblings landing roughly on the sand while Aang landed nimbly in a crouch. Toph grunted once and released the library, falling onto her backside as the tower was sucked into the ground with a loud explosion of sand, leaving a crater where it used to be.

"We got it. There's a solar eclipse coming." Sokka said excitedly as he embraced his sister tightly, "The Fire Nation's in trouble now!"

Aang stood slowly and looked around, his brow furrowing in confusion. He turned his head and took a few steps towards Toph, who was sitting on the ground with her knees pulled up to her chest and her face in hands.

"Where's Appa?" Aang asked worriedly.

Toph made a sorrowful sad and shook her head, her eyes closing tightly. Aang gasped and his eyes went wide, a tear falling down his cheek when he realized that Appa was gone.