Disclaimer: I do not own Portal. If I did, it would probably suck, so just thank Valve that they got to it first XD . I can only lay claim over the original characters and the story. There, I have appeased the Legal Eagle :) . Back to testing.

Author's Note: This is the final edit (3rd May 2012) of the prologue. For those who are new to the story, hello and welcome! This story is indeed a Portal tale, but it has many references to the Half-Life games (but it isn't quite a crossover, so there's no need to panic if you don't know that particular series). At the start it is mainly GLaDOS, Caroline, Cave Johnson, the Testing Initiative and Mark (an OC) that make an appearance, but Chell, Wheatley and Doug Rattmann show up later.

A few notes: this story is heavy on the Cave and Caroline relationship, and follows the Cave+Caroline=Chell conspiracy theory. I know that it is highly unlikely that this theory really is the truth, but I think the idea in itself is quite sweet.

Last of alll, I hope you enjoy reading this story as much as I do writing it!

Prologue

Back to testing...

'You! Yeah, you! I'm the human. You're the computer. You do what I say; it isn't the other way around!'

GLaDOS uttered a silent, prolonged sigh in response. He was a wise-guy, this human. She did not care for wise-guys.

The master computer hung in her chamber, the only dominant feature in an otherwise massive and empty room. Her almost pure white chassis broke through the shadows cast by the only lamp in the room, and she lifted her head to observe the gently arching panels that formed both her one curving wall and ceiling. Below her she could hear the steady hum of the facilities machinery at work.

With a gentle grace she swayed her body from side to side. It was a simple action, but one that helped to quell the growing sensation of anger that a certain human had induced. This human was not, as many would have supposed, the Test Subject that had been so quick to vocalise his thoughts, but rather the human consciousness that lived inside GLaDOS' own head.

Caroline.

'Don't even think about it.' GLaDOS heard Caroline speak, her voice not unlike that with which the computer herself spoke. 'What has he done to you?'

Damn that Caroline. GLaDOS' life had been so simple and enjoyable after she had deleted the unwanted human pest, but soon after she had opened the human vault with the help of her two incompetent robots, Atlas and P-Body, Caroline had suddenly re-appeared. Somehow, and in the defiance of all known logic, the woman had survived. Now GLaDOS was reunited with her conscience, and that conscience annoyed her.

'Well?' Caroline spoke again, her voice a little more demanding than before. 'What has he done?'

'Despite, of course, being an insignificant bag of bones that nobody will ever miss? Oh, not much. Not much at all. He's just annoying.' GLaDOS replied, thinning her bright yellow optic in distaste.

Both computer and conscience watched the Test Subject through the camera feed in GLaDOS' mind. He was stood perfectly still, and had discarded his Hand-held Portal Device to the floor so that he could fold his arms across his chest.

For once in her entire existence, GLaDOS actually missed the dangerous mute lunatic that she had sent away over two years ago.

'Computer?' The Test Subject called. 'I'm waiting for an apology.'

That did it.

With a crash and a faint, almost sickening squelch, the human had been crushed between two wall panels. The startled scream that Caroline cried was enough to make GLaDOS utter a harsh chuckle; Caroline may have been her conscience, but that did not mean that the computer had to care for her opinions. 'Oh, come on.' GLaDOS' voice had an unsettling mirth to it. 'He contributed nothing to science. In fact, he contributed nothing to his life or the lives of others. I did the world a favour.'

The computer could almost see the disheartened look that would have been upon Caroline's face, had she still had one. Once again, GLaDOS chuckled. 'You realise, of course, that the human race is still rebuilding itself?' She asked. 'It does not need morons like him to weaken their already pathetic gene-pool.'

'The human race needs all the help it can get.' Caroline bit back. 'After those… aliens. Oh God, the aliens.'

Yes, the aliens. Shortly after GLaDOS had banished the lunatic from her subterranean facility, the computer had run diagnostic scans of the non-Aperture technology found upon the surface. What she found had greatly displeased her; Earth had been invaded by aliens approximately twenty years previously, and they had greatly reduced the number of new Test Subjects that she could have coaxed into the facility.

But she was digressing. With a quick sweep she cleared away the now shattered corpse of the former Test Subject, and recalibrated the Test Chambers. 'Well all this procrastination has been fun, but now we should return to testing. I do hope this next human isn't a disappointment.'

Caroline sniffed. 'To you they are all disappointments. It was only Miche…'

'Don't. Just don't.'

There was pause. 'You miss her too?'

GLaDOS scoffed. 'I don't miss her. I only mourn the loss of Aperture's finest Test Subject. With her there was so much glorious testing, but she was dangerous and she had to go. Now, if you would not mind, testing really must continue.'

Caroline sighed. 'Fine, just get this over with.'

Test Subject 99. Profile found. Location: Human Vault.