The automatic doors slid aside with a hiss, and 9 mercenaries entered the building. The youngest among them ran forward ahead of the group, looking around the room.

"Is this it?" he asked in a heavy Brooklyn accent. He was from Boston, but that didn't stop him from having the wrong accent, and anyone who questioned it got a baseball bat in the teeth. He was referring to the room the mercs had walked into, which was round, entirely white, and decorated with various plaques and trophies in cases along the walls. The plaques declared the place "Number 1 Potato-Based Science Facility of 1962", among other things. The Bostonian, Scout, went over to sit on one of the benches in the middle of the room, facing a projector screen. "I was expectin' something more…science-y."

The shortest mercenary, Engineer, adjusted his hard hat. "I can assure ya, Scout, this place has seen more than its fair share of science." His voice had a distinct Texan twang to it. As he strode further into the room, he was followed by Pyro, the merc's resident pyromaniac and total enigma. Pyro never removed its asbestos suit and its voice was muffled by the gas mask it wore, so the mercs weren't even sure it was male, or even human. Still, it followed Engineer around like a child and his father. This was probably because Engineer was the only one who could understand it.

"Mmph mm-mmph mmph mmrph hudda hudda huh," Pyro said, interjecting with its own two cents.

"I agree, Pyro. Seems a bit empty for a science facility," replied Engineer, while everyone else had to just wonder what Pyro had said.

"HAAAAAAAAAAAAAAAAAAY!" shouted Demoman, the black, Scottish, one-eyed demolitions expert. He had his hands cupped around his mouth and was shouting at the ceiling. "IF THERE'S ANYONE HERE, ANSWER ME!"

"There's nobody here, Demo," said Soldier, who was looking at a bunch of papers upside down. Soldier was from an indeterminate area of the United States, which he made sure everyone knew at all times. He always wore a military uniform and helmet, which was a bit too big for him. The other mercenaries (collectively known as RED Team) wondered how he could see clearly with it covering his eyes. "These documents say the place has been abandoned for a few years now. I CLAIM IT AS MY OWN!"

"Please do not forget the mission, dummkopf," said Medic, cleaning his spectacles. Medic was German, and always wore a lab coat and rubber gloves. Behind him stood Heavy, a giant Russian bear of a man, whose love for his minigun (Sasha) was well-known, at least amongst his teammates. Heavy was occupied with fitting his trademark bandolier over his bulletproof vest. Medic placed his glasses back on the bridge of his nose. "We are to inspect this place for ze Administrator to see if zere is anything worth salvaging in zis place."

"Yeah, yeah, I got ya, I got ya," said Soldier, clearly annoyed that he couldn't have the place to himself. He tromped his way over to a display case and shoved his face right up close to it, snorting heavily on the glass.

"Well then, where are we supposed ta start?" asked Sniper, who had begun wandering around the room looking at the various things on the walls and in cases. Sniper was a long and lean Australian, a rarity among the muscle-bound, mustachioed people of his homeland. He wore a pair of tinted aviator sunglasses and a slouch hat to keep the sun out of his eyes while aiming his rifle.

"Perhaps in ze most obvious of places," said Sniper's longtime nemesis, Spy. Spy was a 'French bastard', according to Sniper, dressed in a suit and balaclava to mask his identity. Spy's greater-than-thou attitude really grated on Sniper's nerves, not to mention his constant backstabbing. Literally. That was his job, to sneak around and stab people when they didn't expect it. "Why not try…zis room? Seems they are proud of the…science…that went on here." He picked up a business card from a Welcome desk near the entrance, and read it aloud to himself. "'Aperture Science. The Number Two best science facility in the world. There's a hole in the sky through which things can fly'. Well, their science may be top notch, but I can say nothing for zeir rhyming talents." He pocketed the card and tugged at his gloves.

Suddenly, a female voice none of the 9 recognized began to speak to them from hidden speakers in the ceiling. "Welcome to Aperture Science," it said calmly. "We hope that you, potential investor, find much to invest yourself in."

There was silence from the mercs.

"That was a joke. That is what passes for humour around here. You may laugh." The voice seemed irritated. Sniper wasn't sure, but the voice didn't seem to be prerecorded like he originally thought. It seemed both human and robotic at the same time.

"Please direct your attention to the Aperture Science Viewing Screen hanging by the wall there," the voice continued. The lights in the room dimmed as a spotlight came up on the benches Scout was sitting on. The RED Team took seats by Scout on the benches, and the spotlight went out. A video camera slid from a hidden panel in the ceiling and pointed itself at the large canvas screen hanging in front of the 9 mercenaries. The camera began to display a countdown.

"Hey, we get a movie with our tour? This 'science' business ain't so bad," said Scout, earning him a glare from Engineer. The countdown finished, and a tall man with long sideburns appeared onscreen.

"Cave Johnson here," he said, raising one hand in a sort of stationary wave. "Now, we at Aperture Science have heard of the idea of caution. But that makes for bad science. Who wants to wait 17 years testing things safely just to find out something isn't going to work? Not us. We do our science quickly and efficiently." As he said the last sentence, a loud explosion went off in the background, visibly startling him. He straightened his shirt. "…Usually. Other times stuff blows up. But! If it blows up, that means it's working! I think. The lab boys said that once." An offscreen voice mumbled something to Cave, who listened, then scratched his chin and stared to one side. "…My assistant just informed me that we should probably reshoot this publicity video. But here at Aperture Science, we do things right the first time or not at all! Sometimes. Sometimes it blows up and we have to try it again. Or we do it over and over to get it right. But not like other science facilities! We do things—"

The projector suddenly flashed and died, leaving the room in darkness. Soldier leapt at the screen, slapping at it like that would make the video resume. "HEY! Where did that man with the great ideas go?! Do it with explosions or not at all! Brilliant! I was beginning to think I was in the wrong job! COME BACK, MYSTERY MAN! WE ARE KINSMEN!"

The lights began to fade up, and the voice chimed in again. "We thank you for volunteering for testing, new subjects. Please proceed into the next room to retrieve your Aperture Science Element Protection Uniforms and Long-Fall Boots. You will need them for your upcoming tests."

"Tests? Wot tests?" asked Sniper, slowly standing up. "I didn't soign up to take any arithmetic or scoience tests!"

Spy chuckled, lighting a cigarette. "Do not fret, bushman. I don't think they mean school tests. Did you never go to school? Is zat why you are so scared of zem?"

Sniper grabbed Spy's arm and dragged him up. "Listen, mate, I went to a good fourteen years worth of schooling. So I've taken plenty of school tests. Just because I'm Australian doesn't automatically make me a muscley moron!"

Spy didn't even flinch as Sniper got right up in his face. Spy smirked at him. "Do not get your…what is ze word. Knockers? Something like that. Do not get zem twisted. I'm sure if there are any arithmetic tests you'll have no problems. Unless you do. Which seems very likely to me."

"Are you calling me stupid?" Sniper switched his grab from Spy's arm to his lapel.

"If the shoe fits."

"Why you…"

"Hey! You two! Quit yer gibbering and git over here!" Demoman and the rest of the team were already heading into the next room, past the projector screen, which was filled with lockers. A sign above the door read GUEST SUBJECT LOCKERS. Heavy, Medic and Engineer were in a conversation together, while Scout and Pyro were putting on orange jumpsuits. Pyro was putting its on over its regular asbestos suit, and having a bit of trouble. Scout had already finished zipping his up and was modeling it in front of a mirror. Soldier was still pounding on the screen. Sniper released his hold on Spy, giving him a death glare, and went to join the others in the locker room.

"Why is robot lady voice telling us to be subjects?" Heavy grunted, folding his arms.

"I do not know, my large friend, but if our orders are to see zis area thoroughly, zen partaking in what ze facility has to offer is ze perfect way to do so." Medic shrugged and began to take of his surgical gloves.

"But what if the tests are dangerous?" asked Engineer, not fully convinced.

"Worry not, Herr Engineer. Ze Administrator told me before we left that they have set up zis facility to Respawn us. I was suspicious, but when ze voice mentioned…tests, I knew why Respawn Technology was required."

"…What do you mean?" Engineer took a step towards Medic.

"Ze Administrator told me about zem too. Zese tests we will be performing are large rooms with puzzles in zem. Ze puzzles consist simply of 'Escape ze room'."

"Heavy does not like the sound of that."

"We will be given devices that create holes in ze walls. Not bullet holes, but…you will see, Heavy."

Engineer shrugged. "I still don't trust this whole plan, but I am quite interested to see what they do here. I worked for their direct competitor for a while." Engineer took off his helmet and put it inside a locker, taking out the jumpsuit inside. "'Scuse me, fellas, I'm gonna go change in the change room over there." He headed into a more private, sectioned part of the room and closed the door.

"Man, fellas, do I look good, or do I look AMAZING?" Scout crowed, flexing his biceps (what little of them there were) and grinning smugly at his reflection.

"Yes, dummkopf, you look fine. Quit your posturing and strap on your boots." Medic had his suit on and was currently trying to stuff his feet into boots that seemed a bit too small for him. Heavy patted him on the shoulder and offered him some slightly larger boots he had found in a cabinet marked APERTURE SCIENCE ALTERNATIVE FOOTWEAR AND LIFE PROTECTION AGENTS.

"Yeah, I gotcha, I gotcha," said Scout, whipping off his shoes and taking his personal boots out of his chosen locker. Pyro had given up trying to put the suit on and instead was sitting grumpily on a bench with its arms folded. Soldier had come in at some point, most likely due to Demoman convincing him they'd meet the tall man with the sideburns later on.

Two minutes later, the entire team was fully kitted out and raring to go, except Pyro, who seemed annoyed that it didn't get to wear cool outfits like everyone else. The voice came back again.

"Once you have finished preparations, please proceed through the door to the Aperture Science Assisted Weapon Holding Pedestals. The pedestals hold the devices you will be using during your tests." A part of the wall that had been overlooked as simply white space suddenly slid to one side, revealing a long hallway with a number of gun-like objects sitting on, as the voice had said, pedestals. There were exactly nine, each with 2 coloured stripes running parallel to each other down the center of the device. The coloured stripes were all different. "Each guest subject should retrieve an Aperture Science Handheld Portal Device now. Failure to do so will result in death at some point in the future. Probably. Anyway, it's a good idea to pick one up now."

The mercs each quickly grabbed one of the strange guns.

Sniper looked at his device. It was somewhat gun-like, but not like any gun he'd ever seen. It was a combination of black metal and some shiny white plastic. Three prongs extended over the barrel of the thing, like some sort of pincer. There was a glass covered hole in the center of the white plastic, with a green line running down one way and a yellow line down the other. Sniper quickly looked at the device of the man next to him. Spy's had blue and purple stripes. Sniper wondered why the devices needed cosmetic differences to them.

"You are so small!" bellowed Heavy in bewilderment, raising the thing to look at it at eye level. "Where do boolets go?"

"As I said, Heavy, zis gun does not make bullet holes. It makes portals."

"Okay, Doc, you're going to have to explain more than that," said Scout, who was practicing posing with the gun and pretending to fire it with soft pchew pchew sounds.

"Let me put it this way: Shoot vone type of shot, and you make a large coloured circle appear on a flat surface."

"Colored circles? AMAZING! I want one!" shouted Soldier, attempting to find a pump on his device.

"Shoot ze other type, and another circle appears. Then, you can go through vone circle and come out of ze first vone." Medic pushed his spectacles up his nose. "We are to use zis technology to solve ze puzzles zat avait us."

"Quite a fascinating piece of gadgetry," said Spy, who was testing how the device reacted to his invisibility watch. It faded in and out of sight without any problems.

"So, uh, where do we go from here?" asked Scout, frowning and looking down to the end of the room. There was nothing there but concrete.

"Up."

The team was surprised to hear the voice say one single word, and so bluntly. Demoman was the first to make the connection, and looked at the ceiling. The end of long, man-sized tubes sat recessed up in the rafters, like cats waiting to pounce. Demoman suddenly realized he couldn't see where the tubes went; the ceiling was out of sight. The others began to look up as well. Heavy opened his mouth to say something, but the tubes suddenly slammed down over each member of RED team. Demo shouted in surprise, and noticed the others were doing the same, but he couldn't hear their shouts. Some of them, like Scout and Soldier, began pounding on the tubes. The voice returned.

"Welcome again to Aperture Science and thanks once again for volunteering your time as Guest subjects in our Aperture Science Testing Chambers. We'd like to remind you that although you may be guests here, you will not be treated differently in any way from our regular subjects. Meaning Aperture Science will not take responsibility for death, injury, and other minor ailments. Good luck, gentlemen." The voice chuckled quietly. "…Luck can't help you. You boys have been dealt the worst dose of bad luck in history. You've been sent HERE. I hope you realize that.I'll see you in your chambers. By the way…"

The 9 mercenaries were suddenly whisked upward through the tubes, up into the ceiling and into a gigantic room filled with twisting tubes, enormous boxes, and various pieces of machinery.

"…We should be acquainted. I am called GlaDOS. I will be your instructor in these tests. Thank you for helping us help you help us all. Enjoy the ride, gentlemen. It may be your last chance to see each other."

Demoman's tube shot off in a separate direction from the others, and within 3 seconds he was in darkness.