A.N: Basically, it's TimeTravelling!Zuko - but not as straightforward as you might think. There is an actual plot. But it might be a bit confusing and un-obvious until later chapters.

Chapter One: Polar Bear Dog Cubs

The abandoned Fire Navy ship was a dark specter in the snowy landscape, a foreign atrocity in the expanse of virgin ice. It was a reminder that they had been here and that they could come back whenever they wanted to take everything away again. Katara had gotten used to its shadow on the horizon as the backdrop to her everyday life, tainting every mundane moment with the promise that even here, in the frozen bottom of the world, she was not safe from them.

The Tribe had a legend about the ship. It had been part of a raid that took many innocent lives, but it was caught in a storm and stuck in an iceberg, separated from its fleet and left to the mercy of Southern forces. Waterbenders sieged the ship, sealing every exit with ice and leaving the Fire Nation soldiers inside to die of cold and starvation. A hundred years later, the trapped souls of the soldiers still prowled the depths of the ship, waiting to devour the Water Tribe children that set foot in it.

Obviously Katara knew it couldn't be true, but that didn't make the colossal vessel seem any less eerie or menacing. "We're forbidden from going near it," she said as she raced to catch up to Aang. "It could be booby-trapped."

Aang stared at the looming metal monstrosity in awe. "C'mon. If you want to be a bender, you can't let fear stop you." He leaped in the air, a flicker of orange and yellow swallowed up by the hole in the hull.

Katara steeled herself. Bender. Right.

The inside of the ship was a labyrinth of empty corridors and black doorways open like waiting jaws. Their steps made hollow noises against the metal. It was just like how Sokka described it in horror stories, with holes waiting to trap her feet and twisted metal that clawed at her parka whenever she had to squeeze past a tight spot. Something in the depths of the ship clanged, the sound reverberating with phantom echoes from all directions. Her courage drained fast. "Come on, Aang, let's go back. This pla-"

The words died in her throat.

She'd just walked into some sort of barracks - and there was a human-shaped lump on the floor.

Aang rushed in from the adjacent room, alarmed by her scream. "Katara, what's wrong?"

"A-a bo-" Katara stuttered, falling back and scuttling as far away as she could. "A bo-bo-body!" A dead Fire Nation soldier, it was going to eat her – "Don't get close!"

"No, look!" Aang gesticulated. "He's breathing!" Katara watched with wide eyes as, indeed, part of the figure seemed to rise and fall, like a chest moving up and down. Her breath started coming in shallow, panicked pants. The Fire Nation soldier was alive. "We have to save him!" Aang cried, rushing to the figure's side. "Come on, Katara, let's take him back to the village."

"Are you crazy? He's Fire Nation!"

Aang paused, taking a good look at the body he was trying to lift onto his shoulders. "He's wearing Earth Kingdom clothes. And even if he was Fire Nation, he'll die if we leave him here."

Katara moved out of the way as Aang started dragging the body out of the abandoned ship. She hesitated for a moment. Helping a Fire Nation, and- but no, Aang was right. He wore Earth Kingdom clothes. She approached to grab one of his arms and sling it across her shoulders. Aang smiled gratefully from the man's other side.

Not man, boy, she realized, surprised. He was probably around her brother's age. His skin was ghostly white, a sharp contrast to the dark, scraggly hair that hung over his eyes. His features were even and straight, and he would have been handsome if not for the gauntness in his cheeks and purple bruises under his eyes. His lips were a shade worryingly close to blue, and delicate droplets of ice clung to his eyelashes.

He looked peaceful, almost, as if he were sleeping. But when she touched his face his skin felt cold, even through her mittens. "We need to get him warm." They stopped for a moment so Katara could shrug off her parka and put it on the stranger. His limbs were dead and heavy as she slid them into the sleeves.

Between the two of them and with a bit of help from Aang's airbending, they made it to the village in record time. Sokka was waiting for them at the entrance. His eyes widened when he took in their load. "Who's that?"

"We found him in the abandoned ship-"

"What? Katara! You know it's forbidden-"

"We don't think he's Fire Nation. Please, Sokka, he needs help," she said. The boy hadn't opened his eyes, and his breathing was labored and irregular. Katara had noticed a darker patch in his hair that might have been dried blood.

She'd been so scared when she first saw him. If she'd been alone, she might have actually ran instead of helping him. Guilt curled in her stomach at the thought. Good thing Aang had been with her and insisted on bringing him - it was the right thing to do.

And now she really wanted to find out what an Earth Kingdom boy was doing in that ship.

Sokka wasn't having it. "You remember what happened with that polar bear dog cub? What happened when you brought it home, hm?"

"This isn't the same thing. He'll die if we don't help!"

Sokka jabbed his finger at her. "That's what you said about the bear dog!"

Their confrontation attracted the attention of some village women, who formed a circle around them. Gran Gran observed in silence as Sokka frowned and crossed his arms. "He could be a spy. What you've done is irresponsible - you've put the Tribe in danger just by bringing him here."

"It's not Katara's fault," Aang cut in. "If you have to blame someone, blame me." He shifted the weight of the stranger on his shoulders. "But we can't just leave him to die, Sokka."

Sokka looked alternatively at the passed-out boy and Aang and Katara's identical beseeching expressions, and huffed. "Fine. But I'm going to tell our troops to keep him under watch at all times."

Katara's eyebrow twitched. "Sokka, none of your troops are older than five. Aang and I will do it."

They transported him to Sokka and Katara's hut and laid him down near the fire. "He needs to get warm quickly," Gran Gran counselled. "Sokka, Aang, check him over for injuries. Katara, go tell the women to go back to the fishing."

"I think there's blood on his hair-" she started.

"Go, Katara. I will take care of it."

By the time Katara returned to the hut the stranger was buried under a pile of furs and blankets, and a bandage was wrapped around his head. When she laid a hand on his forehead, she was pleased to find it reassuringly warm. She unwrapped the bandage to check the head wound while Sokka went through a pile of clothes in the corner. "This is all he had on him," he said, showing her a dagger. Katara stopped what she was doing to inspect the inscription. Made in Earth Kingdom. On the other side of the blade, Never give up without a fight.

"Told you he wasn't Fire Nation." She returned to her task. He had a cut, like he'd been hit over the head with a blunt object and his scalp had opened.

"But then what was he doing there?"

"No idea," Aang replied, hovering over Katara's shoulder.

"It looks like he was attacked," she said, eyeing his wound with worry.

Sokka stood up, expression set. "I'm going to the abandoned ship. We need to find out how he got to the South Pole and what he was doing here. Make sure he doesn't escape." He left the hut, grumbling about stupid sisters finding troublesome boys in the snow.

Aang slumped a bit at that.

"Don't worry, Aang. I'm sure he didn't mean you."

Katara stayed with the stranger throughout the morning. He slept perfectly still, and his temperature continued rising until it seemed like he had a slight fever. She wiped the sweat on his face away with a cold towel, wondering if he was going to wake up at all. Sometimes people who spent too long in the cold never did. Gran Gran called it the Sleeping Death.

Sokka brought back a pile of things from the ship, which included a teapot, a blue theater mask and a sword. As it happened, it wasn't one blade, but two that fit together, and upon discovering this he started playing around, using them in demonstrations to his class of toddlers. Katara wasn't surprised when he returned five minutes later crying about a cut in his thumb. "You really shouldn't touch other people's things," she admonished.

A rustling sound came from the stranger's corner. The siblings were at his side in an instant. "Hey, are you okay?" Katara asked. "Can you hear me?"

The boy blinked, revealing eyes that glimmered like honey in the darkness of the tent. He opened his mouth, but no sound came out.

"Sokka, get some water," she snapped.

Aang entered the hut with a breeze of air. "Did he wake up? Did he wake up? What did he say?"

Katara took the cup from Sokka and brought it to the stranger's lips, lifting his head with her other hand. "Here, drink this." He swallowed greedily, before slumping back, trembling. "How are you feeling?"

The boy's eyes fixed on her face, and then moved to Sokka behind her, where they rested for a second before landing on Aang. "I'm so glad…" he whispered hoarsely. "So glad I found you." His eyes closed and a sigh escaped his lips.

"He was looking for us!" Sokka exclaimed. "He is a spy!" The stranger twitched in protest, but it seemed he was too tired for any other reaction.

"Oh, shut up and go away, Sokka. He needs to rest."

"No! We still don't know what he's doing here. Hey, you! Wake up."

Katara shot Aang a meaningful look. The airbender made a confused expression. She flickered her eyes to Sokka, and gave Aang the same meaningful look. His face brightened.

"Sokka, I forgot to tell you, I saw the kids playing with one of those clubs you told them not to touch."

"They were playing with my machete?"

"Yeah! That. C'mon." Aang grabbed Sokka's hand and started to pull him out of the tent, smiling at Katara once before he disappeared under the flap.

The boy under the furs relaxed when they left. Katara smiled. "I'm sorry about my brother. Here, have some more water." He drank, and she put his head back on the covers, being careful not to jostle him. "You should rest. I'll be near if you need anything." He gave a barely perceptible nod and was soon asleep.

The boy awoke again some time later, when the sky was already darkening. This time, Katara got him to sit up, and gave him some seal jerky soup. "Thank you," he said. He never looked right at her, using his bangs to hide his eyes. She managed to catch glimpses though, and realized that the irises were lighter than she'd first thought – a gold so vibrant it was almost yellow. He looked around the hut, her scrutiny obviously making him uncomfortable.

"I'm sorry, I didn't mean to stare," she said. "You're the second person I've ever met from outside my tribe."

"No, it's, um, fine." His voice had a raspy quality to it, but it wasn't unpleasant. "I was just… This is where you live?"

"Yes."

His eyes searched the room, looking at the furs and the small fire, and Sokka's stuff strewn around on the floor, and some pants Katara was in the middle of mending slung over a chair in the corner. "It's very… cosy."

She blushed. "Well it's kind of small, we, um, normally we'd be living in the Chief's hut but we've turned that into a nursery-"

"No! I meant, it feels like a home."

Katara blushed more warmly. "Oh. Thanks."

The boy slurped his soup to cover the awkward silence that followed.

Sokka burst into the tent. Aang followed behind him, biting his lip apologetically, but Katara reassured him with a wave of her hand. He'd managed to keep her brother busy for hours; it was more than she'd hoped for. Sokka was carrying a machete and pointed it at them menacingly. "Katara, get away from him."

She sighed, whispered an apology to the stranger and went to stand beside her brother. Sokka glared at the boy, tapping his machete in his other hand. "You're not getting out of it this time. Let the interrogation begin."

The boy sighed and snuggled deeper into the furs. He looked like an overgrown seaprune with a face. "What do you want to know?"

"What's your name?" Aang piped up.

"Lee."

"Nice to meet you! I'm Aang. These are Katara and Sokka."

"Hey!" the latter protested. "I'm in charge of the questioning."

"Sorry."

"Are you Fire Nation?"

He took a second to answer. "No, I'm from the Earth Kingdom."

Sokka started pacing back and forth in front of Lee, trying to seem intimidating, but Lee didn't look at him, didn't look at any of them; his gaze was fixed on a spot on the floor, his features pinched and tight. "Are you okay?" Katara asked.

His eyes lifted, and she could see the moment he took in the three of them, drinking them in. She saw the current of emotion behind his eyes right before he closed them and a tear slid down the side of his face. He quickly wiped it away with his arm. "Yeah," he replied, his voice thick. "I just- I didn't think I'd make it." He took a deep, shuddering breath. "Thank you for finding me."

Even Sokka softened at that. The Water Tribe siblings knew how terrifying the endless ice could be sometimes. Getting lost in the void, with nothing but white pressing in from all sides could make the most hardened warrior go mad... if the cold didn't kill them first. "Hey, it's okay," Aang said. "You're safe now."

Lee looked away, embarrassed. "Thanks."

"What are you doing all the way down here, if you're from the Earth Kingdom?" Sokka asked, though in a distinctly less aggressive manner.

He looked around some more. "This is the Southern Water Tribe?"

"Yes. Well, what's left of it." At this point it was obvious that Lee wasn't an enemy, and he was the second most interesting thing that had happened to her in years (Aang got first place because he was an airbender and might maybe possibly take her to the North Pole) and he seemed like he'd gone through a lot. He should at least know where he was.

Then a thought occurred to her. "Oh! Are you an earthbender?" Maybe he could teach her a few moves, like Aang had been trying to do.

The flare of hope died before it was even born when he shook his head. "No."

"So why are you here?" Sokka persisted.

At this Lee hesitated. "The... Fire Nation destroyed my boat."

Katara's eyes widened. "What did you do?"

"Some things. I destroyed a fire temple, but that part was an accident." He took a deep breath, his hands clenching white on the furs. "I washed up on a chunk of ice. I knew the Southern Tribe had to be somewhere close, but I wasn't sure where. Then I saw the abandoned ship... I can't remember after that. I think walked there, but I didn't have the strength to keep going." He looked up at them, golden eyes wide. "I didn't think I'd find you." They frowned at the odd phrasing, until he clarified, "I mean, the Southern Water Tribe."

The siblings looked at each other, absorbing the story. They had a private conversation in the space of a few seconds that neither Aang nor Lee were privy to.

I still don't think we can trust him.

Katara frowned. How can you be so heartless?

He made a vague gesture with his arm. Well, what do we do with him?

Katara glanced pointedly at the bowl of soup Lee was holding. Nurse him back to health, obviously.

Her brother took a step forwards. "As soon as you can walk, you go back to where you came from."

"And how do you expect him to do that?" Katara protested. "Walk across the ocean?"

Lee smiled, as if there was an irony in the situation. But then his eyes landed on Aang, and the smile dissolved into an intent look. "I understand if you want me to leave. But I swear on my honor that I mean no harm to any of you, or your tribe."

Sokka, Katara and Aang conferred just outside the hut, whispering in hushed voices. "There's something he's not telling us," Sokka insisted, shooting a glance back at the hut.

"Maybe," Aang allowed. "But I think he's genuine when he says he doesn't mean any harm. I have a feeling about him…"

"Sokka, we have to let him stay," said Katara. "He's in no condition to survive alone in the Pole."

"Okay, but for how long?"

A silence descended upon the three as they contemplated the question. Since the men had gone to war, hands had been short for hunting and fishing expeditions. Perhaps they could use Lee's help when he recovered. She sneaked a glance at her brother. Sokka had often complained about the lack of manly men he could do manly things with in the village. Surely he would warm up to the idea of having another boy his age around. The look in her brother's eyes wasn't particularly warm, though. For some reason, he was suspicious of Lee; then again, he had also been suspicious of Aang at first.

Aang provided the solution. "Sokka, I've been thinking, maybe Appa and I could give him a ride back to the Earth Kingdom."

"I guess that should solve the problem... If your bison can actually fly."

"He sure can! He can fly faster than me." Aang hesitated and met Katara's gaze. Her heart rate picked up.

If you want to be a bender, you can't let fear stop you.

She'd been thinking about the North Pole ever since Aang first mentioned it. It would mean leaving her tribe - her family, everything she'd ever known. But it would also mean finally learning to bend. She imagined all she could be capable of if only she had a better grasp of her gift - build entire ice buildings by herself, hunt the largest predators, control the ocean under her canoe.

The true appeal wasn't just the waterbending. She was fourteen, and she hungered for life beyond clearing tables and washing dirty socks. She wanted to know what the world was like beyond their little corner of the ice.

"Aang also offered to take me to the North Pole to learn waterbending," she blurted.

"What?"

She looked away, biting her lip. "Sokka, you don't understand. Not being able to bend properly is so frustrating–"

Anger quickly clouded the hurt in his eyes. "So you would choose your weird magic water over us? Your family?"

"It would only be for a short while! Only a few months - then I would come back."

Sokka stood up abruptly. "Forget it, Katara. Going to the other side of the world? It's too dangerous! We're at war! What if the Fire Nation captures you? Dad said I had to take care of you!"

"Aang will be with me."

"Yeah," Aang agreed, "I wouldn't let anything happen to her, I promise."

Sokka eyed Aang's wide, sincere smile for a minute. "Wow, I guess if the twelve-year old monk says so there's absolutely nothing to worry about then."

"Technically I'm a hundred and-"

"Whatever! The answer is no, and that's final."

Katara's temper rose like an angry wave. "You don't get to make decisions about my life!"

The argument started in shouts and ended in tears and accusations. The two siblings went to bed in frosty silence that persisted throughout the following day, despite Aang's efforts to convince them, trick them, or force them to make up. Katara didn't understand her brother's worry for her safety, and Sokka didn't understand the pull of waterbending in his sister's soul.

To take her mind off her fight with Sokka, Katara spent more time with Lee. After a day he was feeling much better, able to eat solid food and walk around normally. She gave him back his clothes and weapons, watching as he examined his swords before expertly sheathing them in one smooth movement.

Right then, Katara realized something important. She couldn't find a way to articulate it, even in her thoughts - but she somehow could tell that not only did he know how to use his swords, he had used them. There was something contained and quiet in his eyes, and in that moment, she knew that Lee, fragile as he looked now, wasn't harmless.

He insisted on contributing something despite Katara's instructions to stay in bed. He saw her doing the laundry, and decided to help – in the end Katara gave in, since moving around a little would do him some good, and she could use the company. While they worked, he asked her questions about her life in the South Pole, while she asked about his life in the Earth Kingdom. His answers were noticeably shorter and vaguer than hers, but she didn't mind. She'd never had someone to complain to before – Gran Gran essentially told her to suck it up and complaining to Sokka was like talking to a wall.

"I never considered the possibility of leaving before, because it didn't exist. But now that Aang's here, and he has a bison that can fly us there, how can I not go? It'll be dangerous, but..." she grimaced. "It's just, I feel like I could do so much more than just this all day." She waved vaguely at the water in the basin, and it spun lazily following her motion, twisting the clothes floating in it. "I know, it's stupid."

"No, it's not," he replied quietly. "We all need to search for our own destiny. Yours is out there."

He seemed serious. "Uh, yeah. I guess that's..." Her destiny was to go out there, to learn bending, to see the world. A feeling of relief and rightness washed over her, as well as anticipation. Her decision was made. "You're right. It's out there." She smiled at him. "Thanks. And thanks for helping with laundry. I appreciate the company."

"No problem. I used to do this a lot." He eyed a particular grease stain and leaned closer to scrub at it more vigorously.

"How come?"

"Huh?" He straightened. "Uh… I had a friend." He returned to scrubbing, not meeting her eyes. "She used to take care of all this in our… group, for a long time. I helped."

"That was nice of you."

He smiled, and there it was, that hint of irony again. "She didn't think so, at first."

"Why?"

"We didn't start out as friends. She hated me. I sort of deserved it." He was quiet for a minute. "The laundry thing was me trying to make up for it."

Katara hummed. She'd gathered that Lee was a reserved individual, and didn't like talking about his past, so she was a bit surprised by his willingness to share the story. At the same time, she noted the careful lack of context or detail. "What happened to her?"

Lee's mouth tightened, and he closed his eyes.

"I'm sorry," Katara said, realizing how insensitive she was being, given his use of past tense. "You don't have to tell me."

His golden eyes opened, and there was a pained look in them, so full of sadness and guilt and longing. Katara took a step back, surprised. His hand lifted, as if reaching for her, but it stopped in the space between them. "I wasn't fast enough. I should have caught it. I-" he swallowed. "I'm so sorry, Katara."

The intensity of his emotions frightened her. His eyes begged forgiveness, a forgiveness that she couldn't give because she had no idea what he was talking about. Unsure of what to do, or why he was apologizing to her, Katara hesitated, and in the next moment Lee was gone, the cloth he'd been washing abandoned on the side of the basin.

His words haunted her for the rest of the day. I wasn't fast enough. There had been so much regret, so much guilt. She found him two hours later hunched in on himself at the edge of the white cliffs, watching the ocean ripple like a blanket underneath him. An icy breeze blew in from the water, but Lee wasn't wearing the parka they'd given him, she noted with some concern, only his old, ratty Earth Kingdom tunic.

"You must think I'm crazy," he observed.

Katara thought about it. She'd been thinking about it all day. Her mother's face appeared blurred in her mind. I should have been faster.

"We all have ghosts," she replied honestly.

After a while she placed a hand on his shoulder. "Lee… if you ever need to talk about it, I'll listen." She wanted to give him a hug, but they didn't know each other well enough for that yet, so she squeezed his shoulder instead.

"Thank you," he replied, his gaze still lost in the ocean.

They were ready to go. They had packed food, sleeping rolls, cooking utensils and clothes, and everything was tightly bound to the sides of the saddle. Aang was already sitting on Appa's head, holding the reins. Katara checked her small satchel for the hundredth time as she paced nervously in front of the giant bison, creating a trodden path in the snow. They had said their goodbyes to Gran Gran and the rest of the tribe an hour ago. Still, she couldn't bring herself to take that final step and join Lee in the saddle.

"Katara…" Aang prodded.

"Just a while more. He might change his mind."

"Katara, it's been an hour. I don't think he's going to." Aang made sure to speak as gently as possible. "It's not goodbye forever. You'll come back after you learn waterbending."

But he didn't get it. He was an airbender; they were nomads. Used to travelling, to leaving things behind. Katara had lived here her whole life. Her hands clenched and unclenched in her mittens. "I know. I just…" She'd been hoping that Sokka would come with them. Or at least, that he'd come to say goodbye; but he hadn't left the hut, still hurt over her decision to abandon him and the tribe. Katara's shoulders sagged. "Yeah. I guess you're right." She forced herself to turn towards Appa and climb into the saddle.

Lee sat up, looking groggy, having fallen asleep while waiting. "Is Sokka here yet?"

"No," she replied, looking away. "We're leaving."

"What? But he has to come."

Katara averted her eyes and settled herself on the opposite side of the saddle without saying anything.

"Yip yip," Aang called softly.

"Aang, wait, he has to-" but before they knew it they were rising, and Lee's protest was masked by the thunderous sound of Appa's tail hitting the ground and the whoosh of snow lifting.

Katara leaned over the edge of the saddle, watching as her village grew smaller and smaller in the distance. She turned her eyes to the endless sky and breathed in the frigid air, letting it burn in her lungs. A flock of arctic birds flew above Appa in formation, white dots in the vastness of the sky, mirroring the pattern of icebergs in the sea below.

She hadn't doubted Aang when he said that Appa could fly, but to actually experience it was like nothing she'd imagined. Still, her wonder was dampened by her brother's absence. Sokka had always been there. Even when their mother wasn't. Even when their father wasn't. He had been her one constant. The only thing keeping her together.

She was about to tell Aang to go back – she couldn't leave after all – when her eyes caught on a small blue spot at the edge of the coast, jumping and waving his arms. "Aang, turn around! It's Sokka! He came!"

The airbender tugged on the reins, causing Appa to execute a sharp turn. They dove, and Katara was out of the saddle and in Sokka's arms before the bison even landed. "I promised Dad I'd take care of you. I'm not letting you go alone," he breathed in her hair. He had a pack slung over his shoulder, with the boomerang sticking out of the top.

She hugged him so tightly it hurt.

Lee smiled at Sokka. "You're late."

Aang looked back at his three new friends sitting in the saddle and grinned. "Alright, now that we're all here. Hold on tight, ladies and gentlemen, because we're about to take off. Next stop: the Southern Air Temple!"