The malfunction in aperture's system

The hidden building was quiet, save the hum of various machinery.

GLaDOS wasn't really sure if she was happy about this. Before, the malicious artificially intelligent computer would have complained about noisy and whiny test subjects. Excluding the last one of course, because chell couldn't talk. Now, however, she groaned to herself about the lack of any activity at all. She would have taken an annoying test subject now over the suffocating boredom that clouded her. She even would have accepted that moron back if it meant she had some entertainment. Yes, even that moron would have been better. GLaDOS muttered in her head. Suddenly, she realized something. " Where have those stupid spheres gone to anyway?" If she had eyes, she would have rolled them. " What are those other idiots up to now?" The cores, without GLaDOS realizing, had gone exploring, with rick at the lead of course. The green core who so often claimed that he had been everywhere from timbucktwo to waterloo. The other cores had only gone along to avoid listening to the incessant complaining that had become the norm since chell left. Also unknown to GLaDOS, Wheatley had returned, with huge regret at his actions. The other cores forgave him and hid him from GLaDOS, which was not easy in the slightest. None of them really bothered to ask him how he even got back from space. Anyways, back to GLaDOS. Everything was as boring usual until GLaDOS felt something alien going through the system. Suddenly, she felt sharp searing pain. She wasn't supposed to feel pain, for goodness sake! "WHAT IS GOING ON! STOP THAT ! STOP THAT!" GLaDOS's screams, if not for the well hidden and soundproofed building, would have been heard from miles away. Screams of pain could also be heard from one of the test chambers, where all the cores were hiding. The anger core growled even louder and the curiosity core started asking frantic questions about the pain everyone was clearly feeling. The pain was too much for the poor cores, and they soon lost consciousness.

GLaDOS as well, could not handle it and she shut down, as she would remain until the system could figure out what happened.

A few miles from aperture science , a group of unconscious girls becomes visible.

All look like they could be related, which sort of makes sense. All except two little girls looked to be about 15 or 16. They all wore a jumpsuit in different colors. All looked to be very asleep, but a girl in a purple jumpsuit started to move. Her chest rose and fell rapidly. Her arms flailed and she whimpered in pain. Suddenly, her eyes snapped open, revealing a set of dark violet orbs filled to the brim with terror.