Chell ran after them through the dilapidated test arena, each of their boots squishing into mud while hers in particular gave off the occasional screech as the metal springs zinged off of pieces of twisted metal. She lugged the portal gun in both her arms in much the same way they carried their guns, holding it close to her chest as she dodged floor debris. The zombies were right behind her, their howls and rotten breath right in her ear, their disgusting fingers grabbing at her clothing. Up ahead between the legs of her allies there was a smooth bit of concrete where she could shoot, and she blew a strand of hair out of her face in preparation to make the shot.

Also noticing the concrete, Dempsey glanced back and saw Chell shifting the portal gun in her arms. "She's firing!" He yelled.

They ran onto the hard surface, their boots leaving muddy tracks, Chell counting the paces until there was sufficient room for a portal. Then, with the grace of an acrobat, she spun around and fired at the ground directly behind her - but just as the orange portal yawned open and the zombies began to spill through it, her boots caught on something and she stumbled backward.

Shit! she thought, twisting and reflexively throwing out her arms to catch herself. Unfortunately, as she made contact with the ground, the portal gun was smashed from her grip and went skittering across the concrete.

Richtofen was the first to respond, hefting his Thompson and shouting: "Cover her! She needs help!"

For a few moments, pain thudded in her eardrums as he and Dempsey spun and mowed down the zombies that had managed to stumble around her portal. Chell sprang forward on her hands and knees, getting to her feet as she passed between them and ran over to her portal gun.

Chell's eyes widened in horror. The portal gun was half-submerged in a murky puddle, arcs of electricity lancing out from the prongs and snapping as they connected with bits of metal and concrete.

FUCK! She thought, scooping up the gun by the white shell, GLaDOS's voice echoing in her mind: "Do not submerge the device in liquid, even partially."

She held the portal gun at armslength, heavy as it was, and watched with a terror-induced state of shock as a good amount of water drained out of the barrel and splattered on the floor, the arcs of lightning dying away completely.

It took her a moment to notice the gunfire had stopped. Her ears rapidly regenerated, catching Dempsey's voice: "Perfect, even got a couple of crawlers."

Chell continued to stare at the portal gun as he and Richtofen came over.

"Oh, no…" said Richtofen, noticing the state of her equipment. "Zat's not good."

Chell shook the last bit of water out and brought her mind to attention, glancing back at the pile of zombies: she saw two crawlers, one of them trying to dig itself out of a heap of corpses with a single arm, the other bobbing in and out of her portal and hissing.

She turned the portal gun over in her hands, then upright again. The glass barrel was dark, the iridescent orange glow that should have been there absent. Chell held the gun up to her ear and listened, and was thankfully rewarded with some subtle clicking and a dull whir as the parts inside began to fire up. Aiming the gun at another patch of concrete, Richtofen and Dempsey taking a weary step back, she pulled the trigger - but nothing happened. She pulled the trigger a few more times, the disheartening sound of metal hitting metal without the normally accompanying burst of energy.

"What's up with it?" Dempsey asked.

"Could be zat ze power cells are drained," Richtofen offered, but hesitantly as he really had no idea how Aperture technology worked.

Shit, Chell thought again.

"Maybe it'll boot back up in a bit," said Dempsey, "we can cover you until then. I've got plenty of points to buy ammo…"

Chell didn't think that was likely. All of the Aperture tech she'd encountered was incredibly efficient - if it was possible for whatever powered the portals to reactivate, it would have done so by now.

"I'd say buy a weapon off the wall, but…"

...she didn't have any points.

"Very nice, Dempsey, nice and helpful," Richtofen scolded.

"Ah well, I was just thinking out loud. I'd give you a grenade or something…"

...but She'd emancipate it. It was incredibly unfair: GLaDOS had gone through all the trouble of capturing new test subjects and designing an entire new course with a refreshingly new objective, but hadn't given her any way to participate in the new mechanics. She'd tried repairing windows, but the planks didn't respond to her at all, as if everyone else had some sort of implanted computer chip that she'd missed out on. In fact, that was probably the case. All she'd had was her portal gun, which was only now becoming effective in the fifteenth round, and now it the power cells were completely drained.

"Ze good news is that your portals haven't disappeared," said Richtofen.

The three of them looked back toward the orange portal and the pile of corpses, just in time to see a platform rise out of the floor and sweep all the zombies into whatever abyss waited below. In the process, the buried crawler was crushed and the one bobbing up and down was dragged to the edge of the portal and sliced in half, letting out a defeated howl as it died.

"Huh, round's not over yet. Nikolai and Takeo probably still have some over on their side," thought Dempsey.

"Or ze robots - vat were zeir names? Axis and P-Busche?"

Chell shrugged as if to say close enough, still feeling a heavy sense of defeat.

The clearing was in sight! Chell ran through the only viable pathway, her boots shredding the already-shredded ferns and grasses growing out from the floor panels again, the useless portal gun still clutched close to her chest, the heavy sounds of Dempsey and Richtofen jogging along behind her, their guns and buckles clinking and all three of them grunting and panting.

It was an incredibly traumatic experience, more so than GLaDOS's normal tests. The sight of the rotting bodies of scientists was disturbing enough, but for them to be chasing after her with such bloodlust that they'd crawl right through sharp bits of glass and over dangerous metal debris to get to her was all the more terrifying. As she ran, she had to remain constantly vigilant of more clambering into their path, and how to appropriately lead them to one side or the other so there would be room to dodge and run around them at the last possible moment. And all the while, they were yelling, screaming, howling after her, their throats gurgling and split from decay, with so much hunger for her flesh that the only way to get through it all was to ignore the gritty details: do what Richtofen and Dempsey were doing and make jokes the whole time. There was no other way to cope.

As they approached the clearing, the three simultaneously put on a burst of speed to distance themselves from the trailing hoard.

"We're going to have to make this count!" Dempsey shouted, snapping a magazine into place. "Gettin' low on ammo!"

"I am in need of more roundz as vell!"

That wasn't good. Normally, the clearing offered them a brief rest as all the zombies were funneled into a singular cluster and could be shot down with great efficiency. More zombies would enter the testing arena to replace those that were being killed, but it was usually slow enough for them to have a chance to reload first and get a quick breather, and once the three of them decided to get back to running all they had to do was shoot down the one or two that might be blocking the way and they'd be off.

Now, though -

The air thickened with gunfire, each and every shot sending off a wave of pressure that pummeled their eardrums. Chell turned to watch them work, staring as each zombie's head got picked apart by bullets and corpse after corpse fell.

Suddenly, a giant green hologram featuring the symbols "2X" appeared, and Dempsey darted forward to swipe at it with his elbow.

As the symbol disappeared in holographic smoke, GLaDOS spoke over the intercom: "Ya-ay. Double Points. Good for you - well, most of you, anyway."

Chell wasn't phased by the prod.

"Hell yeah, double points!" Dempsey shouted, following quickly with: "uh-oh."

His magazine had run out of bullets, as did Richtofen's a moment later. To make matters worse, more zombies were spilling in from the edges of the clearing, and there wasn't much Chell could do but distract them.

"Cover me, I'm reloading!" Dempsey shouted.

"I need to get more amm-ooo!" Richtofen sang in response.

Moving quickly, Chell ran past each of the incoming zombies. Every part of her was telling her to run away from them, but strategy demanded her to take the opposite action. She circled the perimeter of the clearing, getting close to each one as it steadied itself, which forced them to lock onto her with their glowing orange or blue eyes. In this way, she made herself the primary target for each zombie and began to build up a trail, and as she circled back around toward Richtofen and Dempsey (who were thankfully watching her progress and readying themselves to join in at the appropriate time) she kept herself at just the right pace so they didn't get too far behind and didn't get too close (getting too far behind would cause them to take a more direct route, which would ruin the whole compact-cluster thing she was going for).

As she met up with her allies, they put on another burst of speed and headed for the pathway on the opposite side of the clearing.

"Hey guys, I've only got five more bullets!" Dempsey shouted.

"Ve will need to make a quick detour by the wall to purchase more rounds!" said Richtofen.

"That's all well and good -" said Dempsey, dodging a zombie that had just entered the clearing - "but I don't have any wall weapons."

Suddenly, the three of them noticed something was coming toward them from the pathway: it was P-Body and Atlas, and they had a hoard of zombies after them as well.

"Aw, shit!" Yelled Dempsey, suddenly changing directions and darting off to the side.

Following suit and thinking for herself, Chell ran in the opposite direction, and the hoard that had been chasing after them burst in seemingly all directions. Chell dodged three or four, bypassing the hoard and giving herself enough time to look over at Dempsey - he was swearing and trying to jump through a cluster, the last of his bullets quickly spraying into one of their torsos. A few beats later and he was knocked down, at which point the zombies turned away and converged on Richtofen, who was quickly beaten down as well. Dempsey fired his pistol madly and, with an odd bit of luck, took down the one he had wounded - and another hologram fizzled to life, this one depicting a box with a line of bullets spilling out.

Chell's eyes widened. She slowed her pace, letting the hoard converge on her, then put out another burst of speed and began another lap around the clearing. As she jogged, she took in the situation: P-Body, Atlas, and Richtofen were down, effectively blocking the exit pathway. She could run back the way they'd come, but there was still a mound of corpses that hadn't been swept away yet. She could try to revive P-Body or Atlas and hope they were prepared to open up some portals in some impressively strategic locations, but that was probably asking a bit much.

Still thinking, Chell ran past Dempsey and rushed through the hologram, causing it to burst.

"Wow, two power-ups within ten seconds of each other," said GLaDOS. "Either you got lucky, or I'm going to have to... have a word with the random-probability core. Anyways, Max Ammo. Good for you. Shame none of you can get it, though, seeing as you're all down."

Suddenly, however, the portal gun in Chell's arms shook and rebooted, and a glowing, white light appeared in the barrel. Chell's heart leapt in her chest. The power cells! Sure, they operated off of some highly dangerous radioactive process, but they were the source of the portals and so counted as ammunition!

Chell aimed the portal gun at a far wall way on the opposite side of the arena and pulled the trigger for the blue portal - and, with a tremendously satisfying burst, a stream of light erupted out of the barrel and shot into the distance. Not waiting to see if it hit, Chell jumped and spun in the air, firing the orange portal right at the feet of the hoard.

They spilled into it, most of them getting sliced in half as they collided with the opposite edge of the portal. Chell continued jogging backward, shooting the orange portal again and again until all of the zombies had fallen through and sliced in half. Each time the portal closed and opened again, a zombie would look like it was halfway stuck in the ground before giving off a high-pitched whine and collapsing forward, its torso divided so cleanly that it looked completely unnatural, until a second later when all the intestines and organs sloshed out.

With the hoard of zombies gone (aside from a few crawlers) Chell looked around at her fallen comrades, then noticed that the "2X" icon at the bottom of her AR Goggles was beginning to blink. Thinking quickly, Chell fired a blue portal at the ceiling above the heap of P-Body and Atlas, then an orange portal below Dempsey and Richtofen in turn, sending them crashing down into a big heap. Jogging up to this, Chell began to revive each one in turn, ignoring their cries of disgruntlement at her actions. The zero in the left-hand corner of her goggles climbed with each revival, the points double their normal value (which was pretty high as was, considering what round they were at), and Chell couldn't help but feel an odd sense of wealth.

With everyone back on their feet, the praise finally came.

"Nice shooting with your, uh, portal-thingy," said Dempsey.

"Yes, that vas quite a skillful performance. Did you get any points at all?"

Chell pulled the goggles off her face and held them in front of Richtofen, who lowered his own to look into them.

"Vow, sixty-one twenty!"

"Hey-hey! That's enough to buy Juggernog, and then some!"

Chell shook her head, though. She had other plans - she had gotten this far without their much-praised perks, or weapons for that matter, and she was feeling a bit prideful for once.

"So uh, what are you gonna do?"

All four looked at her quizically, P-Body and Atlas's expressions in particular.

A moment later, all seven test subjects were clustered around a machine, the only sound being a toilet flush and a recording of somebody singing "...there's a bunch of bad things out there, ya need to send to hell!" Then, with a ding! The portal gun emerged from the innerds of the machine, seemingly unchanged but for some glowing etchings that resembled a circuit board on the black metal of the barrel and prongs.

"Well, well, you've gone and upgraded your portal gun," said GLaDOS. "Don't worry, those things aren't expensive or anything. Feel free to do whatever you want with them - drop them in puddles, stick them into strange machines, really, it's fine. Oh, and in case you're wondering, remember how I said do not look directly at the operational end of the device? Well, that's doubly-true now. Let's just say the portal emitting process doesn't stop when it gets intercepted by an incompatible surface anymore. It'll go right through. Zombified corpses, tree trunks, reinforced metal - although I'm not so sure about you, though. It probably wouldn't do anything to you. There's too much to… go through, if you know what I mean. Probably. I mean, look at yourself. Oh, and if you're thinking about using it to escape, don't bother, because I've got the entire testing arena surrounded by Emancipation Grills, and you won't be able to shoot through those. In any case, you probably won't be as useless of a team member anymore. So there's that."

Earlier...

"Hey, Takeo!" Nikolai slurred, waving at his partner as the man shot down the last few zombies chasing him. "I s'think I found s'the perk-machine!"

Takeo came over, kicking a crawler away from his legs and looking from Nikolai to the tall, red machine he stood by.

"Juggernog, excellent!" Takeo remarked.

Nikolai approached the machine and transferred the necessary points in, then waited as the jingle started up. A moment later, a small, brown shape thudded down into where the drink should have been dispensed.

"Vat is this?" Nikolai said, grabbing the lumpy object from the dispenser and bringing it up to his face. A moment later his expression brightened in recognition: "ah, it is a potato!"

Takeo looked at the tuber quizzically. "But, what does this mean...?"

Without hesitating, Nikolai crunched into the lumpy spud, only to reveal the starchy innards to be an unexpected shade of juggernog-red.

"Hey-hey! I'm feeling sstronger already! S'this potato must be a perk! Shame it von't get me drunk, though."

"Perhaps it is... a perk-tato?" Takeo offered.