The night Sokka discovered Zuko sleepwalking was the first time he saved Zuko's life, and for a long while he couldn't quite believe he had. He didn't save him because they were friends, and they didn't start being friends right after. As ideas go, friendship from a non-Aang firebender sounded unattractive and cruel to one's stomach. No, Sokka didn't rescue him because he needed another friend. He did it for the obvious reasons: Aang needed a firebending teacher who wasn't a rabid killer, and Sokka wanted someone to help carry food back to camp because Haru hated hunting and the others were too young. Additionally, it would have been pure irresponsibility to let the jerk die before Sokka learned how Zuko had disarmed him half a minute into their spar, when he clearly had the superior weapon. Even Zuko's crappy life was worth that trick, so when the boy hung from a cliff Sokka hadn't needed to think too hard before playing hero. It happened almost, but not entirely, like this.
When the noise of rustled blankets and boots scraping against stone pulled Sokka from the soft world of seal penguins and fishhooks, it was morning, but barely so. The air was black as pitch, dawn still hours away, but the stars had begun to set and dew was out. Focusing on the sound of someone's door opening across the hall, Sokka pulled himself up from his bed and made his own way into temple corridors.
He followed Zuko quietly, puzzling as he went on the character of Fire Nation citizens and the eccentricities of royalty. Zuko never turned to confront Sokka, even with young hunter-tracker gave up on stealth and simply walked behind the prince. Zuko touched nothing as he walked—doors, walls, furniture. He glided around and past every object, his head bent and his mouth curling around unspoken words. Sokka had not seen a person sleepwalk before, and relished this opportunity to satisfy his curiosity on the subject while garnering a bit of leverage for future blackmail. He tried talking to the older boy, asking where he was, and to his smug delight Zuko answered.
"We're in the summer house. I thought I'd burned it down, but father must have had it rebuilt."
A thousand clever quips came to mind for that, but with no audience to appreciate his wit, he decided to play along. "Why did you burn it?"
"I was angry, of course. It was Mother's house but she didn't need it anymore."
"Why didn't she need it?"
"Because she's gone, idiot." Sokka was certain the firebender didn't know who he spoke to, but he found himself annoyed anyway. He was fifty times smarter than Zuko—he was awake right now, for example.
"Where'd she go?"
"Away." Zuko's pace began to increase; Sokka trotted up beside him. They were getting closer to the terrace-level entrance, and the night air might wake Zuko entirely before this situation could be fully exploited
"Why?" he asked.
Sokka liked this woman already. "What happened to your face?"
The sleepwalking boy's eyes, half-open and lidded, screwed up and his breath came quicker. These questions were upsetting, Sokka knew, yet the prince's voice remained soft and calm, as if he were remarking on tea or the color of sea foam.
"Father did it. You know that, Azula. You were in the first row."
Sokka slowed and then stopped, watching the sleepwalker go. His stomach twisted, his throat shuddered, and he had to lean forward slightly to overcome the faint wave of nausea. Why was the Fire Nation even allowed to exist? Why couldn't Aang turn into a spirit monster and scoop the entire country off the map? This was definitely not worth waking up for, and to say he regretted asking was an understatement.
By the time he looked up again, the scarred boy had vanished. With a mild curse Sokka turned the last corner and pushed through the doors to the terrace. The wide circles of inlaid stone fanned outward, and in the dim, disappearing light of the stars he could just make out Zuko's figure standing on the balcony ledge, talking to a pillar. Sokka cursed again, loud this time, and sprinted across the marble.
The young warrior ran fleet and true, as swift and dark as wolf on the tundra. He got to the ledge, but not in time. He watched Zuko fall before his eyes, a shadowed silhouette sinking into a well of greater shadows. When Sokka finally made it to the balcony rail he looked over and saw his enemy's son, wide awake and terrified, hanging by his life with five rapidly weakening fingers.
"Give me your other hand!" Sokka commanded. Zuko grimaced, swung, and reach upward. His reluctant companion grabbed him, secured him by the shoulder, grunted, and shoved backward with a mighty heave The boys tumbled over the rail to sprawl on cool stone.
Zuko was took deep breaths, sitting in silence. Sokka hoped he wasn't still asleep, because if he was, Sokka was going to punch him awake. He might punch him anyway.
"Why the hell didn't you mention sleepwalking when you asked to join our hero gang?"
Zuko replied, "I dunno," and looked as surprised as anyone, which only irritated the other boy more. "I haven't done it since I was eight or nine."
"Was that when your mother left?"
"You sleep talk, too."
The firebender grimaced—an action that was unpleasant on most faces and only made worse by his disfigurement, which Sokka now had full view of even in the dark—but let it drop.
"This won't happen again."
"You're right," Sokka said, "I'm going to lock you in your room in at night."
Zuko grunted. "Like hell."
"Like tomorrow. A flattened sifu is useless to Aang. But don't worry, I won't let my sister toss the key over the cliff or anything. I'm not a mean guy."
"Generous," Zuko replied dryly, conscious that he could always escape by window if need be. "You're a credit to your tribe."
"You're welcome," Sokka agreed.