Doug Rattmann was still five floors away when the stairs dropped off into nothingness. the nearest door was about five feet from the edge of the stairs, he decided to jump it. He leapt from the steel stairway and held fast to the door frame, he carefully puled the door open and slipped inside. he was in an older hallway, the lights were a lot dimmer, the floors were dusty, and most of the doors were locked. he pulled out his map drawing, there was another stairway down the hall, he set off in that direction. suddenly he heard the sound of screeching metal, he looked around to see where it was coming from, then the floor below him collapsed.
When Doug awoke, he had a massive headache, and his left shoulder stung. he put his hand to his shoulder, it came back covered in blood. he took a look around him, he was in an entirely white room, a testing track. "found you" he voice resounded through the chamber, as she said this the entire room looked like a rubix cube, the walls and floor started shifting and changing, a door grew out from the wall, and a portal gun lay on the floor before him. "when I said I would kill you if I found you, I lied, I'm just going to test you now" Doug picked the oddly shaped machine up and examined the test, he solved it instantly. he shot a portal at the wall next to him, then one up at the ledge on the ceiling, once on the ceiling, he shot a portal on the floor and one on the slanted panel, and jumped into the floor portal, shooting him out of the slanted panel, and straight to the door. the next chamber was much alike, except he had to first launch himself at a cube on a ledge, then at a button, then the door. next chamber. the third chamber was quite a bit harder than the last two, from where he started, there was a portal surface below him, a slanted one above him, a platform with a button across from him, a portal surface below that, a button activated slanted platform across from the exit door, and two sentries guarding the door. the problem wasn't solving the test, that was easy, simply shoot one below him and on the slanted panel, vault across, push the button, get to the door, then take out the sentries. the problem was, that Doug wasn't wearing long fall boots. solving the test would kill him. he decided to try it anyway and hope he landed it right. while soaring through the air the first time he had an idea, he did the rest of the test but this time, when he flew towards the door, he turned himself to the right and drop-kicked the one sentry, before the other one could react, he ducked and knocked it over, with his fist. the door slid open. "very good, those were some very interesting results, I do believe that you are the only test subject brave enough to fist-fight an android with dual machine guns. begin the next test"
Doug walked through the door, not knowing what to expect. what he found was the door was on a ledge, too hight to jump, there were two cube dispensers, and a cube only button leading to one dispenser and a sliding metal panel in the upper wall. but the most important thing in the room, was the grate leading to the vent shaft next to the door. "an aperture science weighted companion cube will be given to you in three... two... one. please take care of it" the first dispenser opened, and a little metal cube with hearts on it fell form the ceiling. Doug picked it up, at firs it sounded like it was singing, but it was probably just the test chamber. He walked over to the cube button, and placed the companion cube inside, a regular cube came out of the second dispenser, he put that cube in the button, and used the companion cube to get onto the platform, then pulled it up after him. "Well done, now, to continue, please place the aperture science weighted companion cube into the incinerator" Doug couldn't believe what he was hearing, she told him to care for it, then burn it, he looked at the grate, now or never. he used the end of the portal gun to pry open the vent and crawl inside, the cube barely made it inside, but Doug crawled onward. eventually, he got to an open room, looking around, he saw that it was an air pump control room, with only one exit, an open metal door, which was closing fast. he had to wedge it open with something, but what, he looked at his hands. on the left, the cube, He was sure that it was singing to him now. on the right, the portal gun, a wormhole tunneling device that could be the demise of GLaDOS. a friend. or a weapon. there wasn't much time to think, the door was closing. he quickly thrust out his right hand and the door stopped. he slid through and kept running. behind him, he heard a large crunch, then an explosion.