"Oh, hey guys!"

"Sokka…what are you doing?" Aang jumped out of the hijacked lift in disbelief at he was seeing, watching Sokka systematically dismantling an Emancipation Grille projector, a turret at his side.

"What's it look like I'm doing, I'm bustin' me and Fluffy McSnoodlepants outta this joint!"

"Hello, friends," the turret warbled.

Toph stepped forward, planting her feet firmly on the floor to get a vibration-shape of some peculiar ovoid with three spindly legs. "What is that?"

"It's a…shooty thing," Sokka announced decisively. "But I disabled him so he can't shoot me."

"And you named him 'Fluffy McSnoodlepants'?" Toph scoffed. "Yeah, I think this place has definitely gotten to your head."

"No, this is normal for me," Sokka reminded her irately. "I didn't know you guys were here, too. Have you found anyone else?"

Aang shook his head as he crouched in front of the disabled turret, waving his hand curiously in front of its eye. "Uh-uh. Toph rescued me and we broke into one of the lifts, trying to find a way to get up to the surface faster."

"Then I heard your voice so we stopped on this level," Toph finished. "Man, I can feel your whining from like a mile away."

"The surface…" Sokka stopped his tinkering and glanced up at the earthbender incredulously. "We're underground?"

Toph picked at her ear, looking bored. "Yeah."

He craned his neck to stare at the ceiling. "How far underground?"

"Pret-ty far."

"Do you think anyone else is in here?" Aang wondered, gazing around at the other turrets strewn about on the floor. Sokka's handiwork, no doubt.

"If they were, how would we find them?" Sokka asked. "Hold on a sec…" He gave the circuitry of the emitter a firm stab with his boomerang; the circuitboard fizzled and sparked and the grille died. With a satisfied smirk, the young Water Tribesman sheathed his weapon and picked up his turret, carrying it safely and vaporization-less to the lift. "Let's go."

"Why didn't you just do that in the first place?" Toph asked as she and Aang followed him; the round space was obviously just meant for one person and the three of them meant things were a little cramped.

"I wanted to see how it worked, first…" Sokka trailed off as he saw the large hole that had been ripped in the ceiling. "…You guys have been busy."

"Obviously not as busy as you, Mister Talks-To-Shooty-Things," Toph replied dryly as the lift began to rise. "And I found Twinkletoes here talkin' to a cube. Have you all gone nuts on me?"

"Sokka, you, you didn't euthanize your Companion Cube, did you?" Aang asked, looking up at Sokka pleadingly.

"My what?"

"You, uh, wait, did you go through a testing chamber where you had to carry a cube everywhere? And, um…the spirit told you it might start talking?" Aang began to feel a little sheepish, and he scratched the back of his bald head.

"Nope," Sokka replied. "I just got this weird device," he jabbed his thumb at the portal gun strapped to his back, "and ended up in a room full of shooty things. Although, who knows where that psycho might've put me if you guys hadn't found me."

"So do you have a way to find anyone else in here?" Aang asked Toph.

"Mmmmaybe," the earthbender replied. She cracked her knuckles, and reached out with her foot and stomped hard. They all waited for a few moments as she concentrated. "I think…there's someone else moving around in here, I can feel their footsteps, barely. They're below us. Oh, wait—one more person. They're fainter. Farther down. I can't tell much else," she shrugged.

Suddenly, the lift jerked, stopped, and began moving downward; Toph instinctively jutted up the metal floor beneath her, launching herself out of the hole she had created earlier and gripping the top of the lift with her feet, clinging to the side of the shaft and digging her fingers into it, dragging the lift to a halt, a feat that made her grunt with exertion.

"I have a surprise for you," GLaDOS announced. "If you hurry, it might not be a tragic surprise."

"What do you mean?" Aang asked. He and Sokka could feel the lift twitch and jolt between GLaDOS's efforts to move it and Toph's efforts to keep it still.

"Your friends are here, being tested correctly."

"Our friends? Who?" Sokka inquired, clenching his fists. "Katara, Suki?"

"Oh, I think you know them very well," GLaDOS replied, covering up the fact that the names meant nothing to her. "They were just asking me about you, actually. In fact, since you've all been such good test subjects, I'll let you complete the last testing chamber and receive your congratulatory cake…together."

"She's bluffing," Sokka deduced. "She just wants us to play into her hands…or…lack thereof. Hey lady, do you have hands or are you just a disembodied voice?"

"It depends on your definition of 'disembodied'."

Aang placed a hand on Sokka's shoulder. "But Toph felt other people down there. Even if it isn't anyone we know, we can't leave them here." He screwed his eyes shut. "I'm not leaving anyone else behind."

"Your Companion Cube misses you," GLaDOS commented. "It's so alone and companionless right now."

"Well at least it's not dying in a fire!" Aang replied exasperatedly. He looked up through the hole. "Toph…let it go," he said. "We have to save whoever else is down here. I'm not leaving without them."

"But…" Toph gasped, trying not to lose her concentration.

"What if it really is our friends down there? I can't take that chance, and I can't abandon anyone again," Aang decided resolutely. "Let's go."

Toph took a deep breath, and sighed, pushing herself away from the wall as the lift began moving downward again. "Fine." She turned and dropped back to her friends. "This had better work, Twinkletoes."

They only had to wait a few more seconds before the lift slowed to a stop again. "Surprise," GLaDOS stated neutrally as the lift doors opened, revealing a test chamber decorated in scorch marks. Several glass panels were partially melted, and in the middle of the room were the charred remains of what might have been a turret.

"Don't look," Sokka warned his own turret protectively, placing his hand over its eye.

"One of your friends is about to receive his victory incandescence. You wouldn't want to be late for that," GLaDOS suggested.

"Victory incanhoozit?" Sokka fumbled.

"Come on, let's do this!" Aang proclaimed, launching himself at the glass and blowing it out completely, soaring through and sending out jets of fire from his hands and feet to propel himself along the hallway on the other side, leaping from wall to wall. Toph scrambled toward the pane and flung herself out of it, digging her fingers and toes into the opposite wall and crawling along it sideways.

"Whoooohoooooonever mind!" Sokka yelled as he began to run heroically toward the shattered glass panel as well and then realized at the last second that the floor of the hallway was covered in an acid pool. Arms flailing, he balanced himself back on the edge and sighed, hanging his head. "Fine, go on without me," he whined. Brow furrowed, he went back to the other side of the room and punched the red button on the fire-blasted stand, hopping, disgruntled, onto the half-melted platform that had begun to move.

"I'm still here," Fluffy McSnoodlepants reminded him from its position on his back.

"At least someone didn't abandon me," Sokka sniffed as he placed portals on blackened wall panels.

"Zuko!" Aang called out in shock as he watched the young firebender calmly riding a platform to his fiery doom.

Hearing Aang's voice, Zuko turned around swiftly, not skipping a beat as he let out a kiyah and thrust out his fist, the one that didn't have the portal gun on it, sending a stream of fire at the airbender. "Avatar!"

"What are you doing?" Aang cried out in alarm, twisting himself to blast a jet of air into the acid, which boosted him toward the ceiling; a split second after he did so, a metal plate with wicked spikes stabbed out of the wall where he had just been, impaling the opposite wall with a sickening crunch of crumbling concrete.

"Saving your hide, that's what!" Zuko barked. "Get up there!" He pointed to a small alcove past the fire pit. "Don't worry about me, I've got this covered!"

Aang grinned and nodded, landing on the retracting arm of the mashy spike plate and shooting a blue portal at a nearby broken wall panel, and an orange portal at one of the concrete panels lining the alcove. Leaping from the wall, he wrapped the air behind him and shot out through the portal, floating gracefully to his feet on the other side.

Just as the flames were licking at the bottom of the platform Zuko was riding, the young Fire Lord yelled ferociously, gathering his energy and sweeping his arms and then his entire body around and upward. The fire gathered and twisted around him and whooshed into a spiraling vortex that carried him to an even higher part of the chamber, where he leaped onto a mezzanine.

"Well played," GLaDOS remarked noncommittally. "Now please assume the Party Escort Submission Position."

"I've had enough from you!" Zuko snarled. He leaned over the decrepit railing and looked down at the airbender. "Come on, Aang, let's show this maniac what we're made of."

Aang looked back at him, hesitant. "Toph and Sokka are here!" he explained. "And I don't know what's taking them so—" He was interrupted by said Toph, clutching Sokka around his middle, suddenly tumbling out of the portal and on top of him.

"Oof…" Toph moaned, rolling out of the dogpile. "Didn't see that there, sorry," she apologized to Sokka.

"No problem," Sokka grunted, lifting himself from the poor crushed Air Nomad beneath him. "I'm just glad you came along when you did."

"Should have guessed you'd be too thickheaded for this kinda stuff," Toph remarked.

"Hey!" Sokka replied defensively. "We all have our off days, and I'd like to see you stare down a room full of of shooty-things and survive."

"I can't really stare down anything," the earthbender reminded him.

"Enough banter, let's get this over with!" Zuko urged with a scowl. "You're all acting like this is a picnic!"

"Right!" Aang looked up at the tall ceiling and immediately got an idea. Shooting his blue portal at the topmost panel in the alcove, facing the mezzanine, he grinned and blasted through the still-extant orange portal in a gust of wind, launching himself clear over the fire pit and coming to a landing beside Zuko. "Think we'll get to keep these when the test is over?" the young airbender asked, hefting his portal gun with a grin. "That was fun."

Zuko merely sighed and shook his head in lighthearted exasperation. "I think we've got bigger fish to fry, first. Figure of speech," he hurriedly amended when he saw Aang's distraught expression at the mention of having to fry fish. "Your turn," the Fire Lord shouted down to Toph and Sokka.

"No, stop," GLaDOS droned. "As fascinatingly unnatural as this is, you're going about it all wrong. I'm going to have to mark your testing as a complete failure. You don't want that, do you?"

No one was really listening to her at that point.

"I got this," Toph smirked, hooking her arm around Sokka's waist again. "Hold on."

"What, why," Sokka began to say, when Toph suddenly jabbed the metal arm they had been standing on, up and at an angle, so they were flung in a tall arc over to their friends, Sokka screaming all the way. "You could have warned me first!" he sniveled as she stuck the landing and set him down unceremoniously.

"What's the fun in that?" she asked slyly before shifting her feet, grounding them in the platform. "We don't have much further to go, I think. Someone's still moving around down there."

"You're too late," GLaDOS boasted. "Your little friend put up a valiant struggle, but in the end she became a glorious statistic in the name of science."

"Liar!" Toph shouted, stomping her foot and sending outward all of the arms supporting the wall panels in the alcove, leaving them dangling and twitching helplessly like a stranded many-armed creature. "You can spout all the crud you want, doesn't mean we have to believe it!"

Suddenly, the vibration of footsteps stopped. Toph's face fell, and everyone else realized by her expression what had happened.

"No…no!" Aang cried, blasting a nearby door down with a burst of air. "We might still have time!"

"For the Companion Cube!" Zuko shouted, almost sounding like he was going to cry, earning him a "oh, not you, too" expression from Toph (and a vindicated look from Aang) as the four (five, counting Fluffy McSnoodlepants) descended deeper into the complex, into areas never meant to be seen by tested eyes.

The little group of vigilante test subjects raced through the maw of the testing facility at breakneck speed, utilizing every trick up their extremely versatile collective sleeve. Toph quite literally bent most of the facility to her whim; Aang and Zuko shot fire and air and themselves through portals, finding paths where there would be none for an ordinary human being; Sokka spent most of the time consoling his turret but did find a use when something needed a good old-fashioned bludgeoning—or boomeranging. And all the while, GLaDOS's voice echoed, faint and desperate, like they were all crazy and she was the last vestige of sanity in their minds, or like they were all sane and she was the insanity creeping in, they didn't know which.

But they kept going.

Finally, they breached a doorway, Toph tearing it off its hinges and casting it aside, and ran down a long hall, and then—there she was.

Or, rather, there both she's were.

"Put me down, you maniac!" Katara screamed, her hair disheveled, suspended by the back of her collar from a large claw at the end of a cable, firing her portal gun pointlessly and angrily at the large, smooth, bone-white ceiling fixture that was staring at her with one emptily-malicious yellow eye. "I hate you!"

"Fascinating," GLaDOS remarked. "Although, in all honesty it's not really ithat/i fascinating. Did you know that hatred is the third-most common emotion experienced by test subjects at the time of their victory incandescence? Which you ruined spectacularly, by the way."

"…What are the first and second most common emotions?" Katara asked curiously.

"Panic, and hunger, in that order. I'm not quite sure why hunger ranked so high. The testing doesn't take that long, taking into account a reasonable level of competence, and there is cake at the end."

"The cake was a lie!" the waterbender bellowed, full of disappointment.

"KATARA!" Aang yelled, scrambling into the room with the others following.

"Aang!" Katara craned her neck, straining to catch a glimpse of her friend.

"You're alive!" the airbender exclaimed with glee, watching her dangling from the cable. "No wonder Toph couldn't feel your footsteps!" He laughed with relief.

"Aang…THERE'S NO WATER IN HERE!" Katara hollered, at her wits' end. "Also, get me down!"

"Not a problem!" Sokka announced proudly, hurling his boomerang. It sliced through the cable and sent Katara and the claw falling, and she landed crouching on the floor, still aiming her portal gun at GLaDOS.

"Okay. You've more than proven that I am not affected by the Aperture Science Handheld Portal Device. I think you can put a rest to that independent testing initiative now," the AI informed her, as Toph curiously picked the claw up from the floor and shoved her hand into the metal, using her bending to make it snap open and shut like she was some sort of bizarre mutant lobster. Aang fell over laughing and even Zuko cracked a smile. "We are also not testing for the effects of superheroes on this facility," GLaDOS continued irately. "You outperformed all of my expectations, and I am very, very—FZZZZT-displeased. As such, before you have the chance to cause even more damage, federal regulations require that I terminate you all. I hope you enjoy the sweet scent of neurotoxin."

"Neurowhatta?" Sokka asked, scratching his head.

"I don't want to stick around long enough to find out what anything with the word 'toxin' in it is," Zuko pointed out.

"Too late," Katara groaned, watching as a bizarre green gas began to pour out from nozzles around the room. "We've got to find a way out of here, a way to stop this thing!"

"You have three minutes to live. I suggest just lying down and assuming the Party Escort Submission Position right now. It'll make cleaning up easier."

"I know!" Sokka pointed out a small hatch on the far side of the room. "I bet that leads somewhere…" He noted the small cores attached to GLaDOS that were looking at everyone with differently-colored, unblinking electronic eyes. "And those are probably crucial to this machine's system…"

"Go on," Katara urged him.

"So…we need to steal those little roundamabobs and…escape down the hatch with them!"

"Or we could have Aang go into the Avatar state," Toph suggested flatly.

"Too easy," Sokka dismissed her. "That would be a total deus ex machina We have to think of something more clever and unexpected."

"Tell that to our resident Avatar," the earthbender replied.

Sure enough, Aang was getting his glow on. "Nobody…nobody messes with my friends like this!" he screamed, his eyes and tattoos illuminating as he began to rise above the floor.

"I've compiled a list of precisely three-hundred-and-fifty-two reasons why you should not do whatever it is you're doing," GLaDOS said in a panic, her eye locking on the mysterious boy. "You should at least listen to them first."

"Guys, get close," Aang directed his friends as a sphere of air began to form around him, followed closely by concrete and other debris from the room being gathered up into the swiftly-rotating shield as well. "Hurry!"

As they complied, Sokka stumbled and the turret was knocked from his back. "No! Fluffy McSnoodlepants! I swore I would protect youuuu!" he wailed as Toph pulled him into the sphere.

"Good-bye!" the turret sang, looking up at him plaintively from where it had fallen.

"Man, what is with you guys and getting attached to inanimate objects," Toph groused.

"He wasn't inanimate!" Sokka retorted. "His eye clearly moved!"

Aang let out a shout and the orb shot straight up, bursting through the ceiling.

"Whatever you're doing, stop it right now," GLaDOS snapped as the sphere began to rise higher and faster. "I'm warning you. You won't like what's up there. You're far better off staying up here and dying with dignity. You think I enjoy this? No one misses you, you know. Think you're playing hero? There are still so many others you haven't rescued. In fact, seeing all of you test has given me wonderful new ideas for an expanded testing track, incorporating all of the elements each of you faced separately. You should give it a try, it will be fun! Come back! No, honestly, come back! There really was a cake!"

The orb crashed through layers of concrete and metal, sent acid spraying away, too fast to be registered in turrets' motion detection. To its occupants it felt like the ascent took forever, but finally there was one last blast of soil and asphalt and then the sky, fresh blue and welcoming, and in a rain of rubble they were tossed to the ground, dazed.

"Wherever that was…let's never go back," Toph moaned. "I've never been happier to be above ground."

Zuko sat up and rubbed his head. "I don't even know how we got there in the first—Uncle?"

"The first uncle?" Katara repeated, confused for a moment until she too sat up and saw what the firebender was seeing—his uncle Iroh, seated on a blanket on the asphalt nearby, with a picnic basket and a pot of tea, looking completely unruffled that an Avatar had just burst through the ground fifty feet in front of him.

"Uncle, what are you doing here?" Zuko asked incredulously.

The older man looked over at his nephew and grinned, pouring himself a steaming cup of tea. "What took you so long?"

Zuko stammered for words but none formed. Everyone else felt much the same way as they picked themselves up.

"Tea, anyone?"