Tests. Keep on testing. They needed to escape. Destroy GLaDOS. That was Chell's plan at least. Sierra had…other plans in mind. Someone would eventually die, but it would not be GLaDOS. She refused to let her mother kill her.

Sierra had become insane, thinking all humans were humans were evil and cruel. She hated humans. Wasting precious time on idiotic things, like games, texting, it was sickening. Research needed to be done. Science was important, there would have to be changes in the world. This world was corrupt.

GLaDOS was with Sierra's plan, she knew Chell would be hard to kill, she was a stubborn human. GLaDOS was happy to get rid of her. Sierra would become an android, and they could find new test subjects, and do research all the time. Sierra wanted that, she wanted to rebuild Aperture into a new facility, and she could do it forever, once she converted her brain into the robot.

GLaDOS had built the body, now Sierra just had to step away from her mother in order to get to it, but Chell wasn't letting her out of her sight. She kept her close. Sierra had to figure something out.

Sierra had to figure out how to make it look like an accident, and escape to GLaDOS, but the tests were concealed in so, there wasn't to much of a way out. Then Chell spotted a vent. Was that supposed to be there? That was a way to get to GLaDOS. Why was it there? The tests were supposed to be sealed. Chell didn't question it though. She found her way up there with her daughter and the went through the ducts.

Chell had to find a way to shut GLaDOS down without her being one step ahead. First they had to go shut off the neurotoxin.

It took a little while to find the control room, but they managed to find it and shut down the neurotoxin levels. When Chell left the room, Sierra turned it right back on. She was done with these pesky little games. She had to find some sort of weapon, in order to win this one. Chell was thinking the same thing too, only this was to destroy GLaDOS, the incinerators weren't there anymore, so there had to be something else.

They then found their way into the main labs. It was huge. The labs were enormous, Sierra was amazed at it. Then a man's voice came on. It was Cave Johnson. Sierra wasn't sure who he was, but she liked this guy. Combustible lemons? I like this guy, Sierra thought and smiled. She wanted to go searching for a weapon, any weapon would do. She had to get away from her mother though.

"I'm going to look for a weapon, something to destroy GLaDOS," Sierra said. Chell nodded and let her go. She's more of an idiot than I thought. Oh well. The stupidity of mankind was about to become…extinct, anyways. With that, she went off on her own.

Sierra went around the building looking for some sort of weapon, but couldn't find anything. Just gels, cubes, and radios. She couldn't do anything with this. Why didn't Cave have any weapons. The only weapons she could find were malfunctioning turrets, and the neurotoxin. She gave up after that and decided to go back to GLaDOS.

Chell walked around, wondering where daughter went. Maybe she got lost. She would destroy GLaDOS, and look for her afterwards, hopefully she was safe. She walked around into the offices, trying to search for some weapon other than a portal gun. The portal wasn't really a weapon. It couldn't really help with a fight, unless GLaDOS was throwing rockets or bombs around. Highly doubt she would try doing that again, since it ended up killing her the last time. Chell kept trying to look around for a weapon, any weapon, just to kill GLaDOS.

Could she just reattach the corrupt cores? No, GLaDOS would just try to kill her. She needed to escape. Somehow.

Sierra got back to GLaDOS. The android was done. It looked exactly like her, it was scary. She was scared, and excited at the exact same time. She couldn't wait to take over. Everyone at her school who made fun of her and science would all pay. No one could stop her.

Chell thought of something, maybe she could somehow rewire GLaDOS, shut her down and take her out of her body again. It was risky, but it had to work. Somehow.

Chell found an electrical rod. If she could somehow hit GLaDOS' brain with it, she could shut her down, but only for a little. Then she could rewire her, and they could escape. Though, she would probably have Sierra do that, she was better with science and machines. She made her way to the main controls, where GLaDOS was. But once she got near the controls, she got trapped.

"Seriously now, you get yourself trapped again, truly you are not that bright," GLaDOS said. "So here we are again, two friends wanting each other to die," she said, "but I'm afraid, I'm not the one who will die." Chell was ready to fight. She had to figure out how to get to her head and disable her brain. Then she saw Sierra.

Sierra was trapped in another box, looking at her mother and crying. Sierra looked scared. GLaDOS put down turrets in front of Chell's box. They were still malfunctioning, and the caught fire, exploded, and broke the glass. Chell escaped and had the electrical rod in her hands.

Sierra's box was lifted. She got out after her mother escaped. She saw the rod in her hands, and knew what she was going to do. Sierra had to react quick, and Chell knew she only had one shot. Sierra jumped in front of GLaDOS and was electrocuted.

Dun Dun Dun what now? Guess you got to wait and see ;)