She was electrocuted. Her mother electrocuted her. It hit her heart. She collapsed on the ground. She felt hurt, she was going to die.
"This can't be happening," Sierra said, "it just can't be happening." Her heart had been slowing down, but she refused to give up. She was going to go through her plan. Chell tried to help her get up, but was pushed away by Sierra. She had the look of hatred in her eyes directed at her mother. She was done fooling around. She wanted her dead. "You were trying to kill me all along didn't you," Sierra said. Chell shook her head. "Well it's alright, I guess we were both thinking the same thing then." Chell couldn't believe it, her daughter was trying to kill her. Wheatley was right when he said she insane.
"Killed by my own mother, who would've known," Sierra said, "though, after my first death, I will live forever in a new body, don't worry though, this little battle will not be forgotten." She was crazy, her mind was corrupt. Her heart kept slowing down, then it stopped, and with that she collapsed. Chell didn't want to leave her daughter, but she was dying, and had gone crazy, she had to escape.
Chell ran and found the elevator shaft, and got in it. GLaDOS didn't stop her either. Instead she was focusing on Sierra. She brought out a body, that looked just like Sierra. GLaDOS worked fast, and Chell escaped.
Chell cried on the way home, she lost her daughter. Sierra was working together with GLaDOS. Sierra tricked her. She electrocuted her daughter. And she died. What was GLaDOS doing? Did she turn her into a computer as well? Chell was upset, and confused. She didn't know what to do anymore. She carried the portal gun home with her, and just sat down, not knowing what to do without Sierra. She regretted not saving her, but she wasn't her Sierra anymore, she was a cold blooded killing computer now.
Sierra woke up hours later. She had died. Her mother killed her. When she woke up, she found her corpse lying on the floor next to her, and she smiled. She accomplished her goal, she was now a living walking android. It was still her, but more knowledge, and power, and she was able to live forever. She could rebuild Aperture Science labs with GLaDOS by her side, and keep test subjects trapped. She could finally do what she wanted. And she knew what she wanted.
She would wipeout the human race. First one to die, her mother. She would take her revenge no matter what.
~End~