A/N: Yeah, yeah, insomnia makes you do some crazy things. Like write something way longer than you usually do. I was replaying this game for my second time and felt compelled to do a more in-depth study of GLaDOS's journey from crazy bitch to slightly less crazy bitch. In all seriousness though, she's fantastic. I decided to follow her psychological progress all the way from Portal to the end of Portal 2. Some of it is kind of recappy at times, but it's mostly a look at her as a character. A rare gem among video game females.

Oh and if you like, please review? I'm kind of new to the non-romance genre so...yeah. *sweatdrop* I will reply to all that I receive, although my laptop charger has become self-aware and stopped working precisely on the week when I'm writing term papers...so might be a small delay while I get a replacement. I swear to God, it's laughing at me.

Disclaimer: Uh. Valve owns Portal. I do have a companion cube shirt though.

"Things do not change; we change." ~Henry David Thoreau

Awakening test subject #122-7605 from her dreamless slumber in Aperture's dusty relaxation vault, the sentient supercomputer wasted no time in launching the standard welcome. "Hello, and again welcome to the Aperture Science Computer-Aided Enrichment Center…" She loved to be benign at first, put on the pretense of standard procedure and courtesy. If there's one practical thing humans had taught her, it's that their guard is piteously lowered by a comforting female voice. It's an unnecessary variable in her data, but infinitely useful in motivating the test subjects.

Motivation…perseverance…tenacity. Her brilliant mind ran through the synonyms. She had grown impatient with unmotivated test subjects. They failed early on and deprived her of the test-satisfaction she craved. These results were unacceptable, yielded no qualitative information except new ways in which humans could meet their end.

In the small glass chamber, the new test subject stared in a daze up at the camera. A female with dark hair and eyes, common phenotypes in humans. Despite her obvious disorientation, there was a hardness in her expression that distinguished her as different from the many before her.

GLaDOS opened the portal, setting the woman free to begin testing. After all this time, maybe she finally had an exceptional specimen to work on.

x x x

Her hypothesis about the unusual nature of this subject panned out as correct relatively early in the test process. Nothing new, of course. Humans were dreadfully easy to predict, no matter how superior they saw themselves to their evolutionary predecessors. Their range of emotions, what motivated them. She knew them inside and out.

However…that did not mean these results didn't pique her interest. The young female, "Chell," as her file denoted her, solved each trial with speed and accuracy that exceeded the average test subject. Through the first few tests, the AI praised her in a way where the sarcasm was only thinly veiled. It irritated her that humans required so much encouragement. Only one of many flaws that plagued organic life.

Yet, as the tests grew more and more challenging, she found positive reinforcement less and less necessary. The woman had easily propelled herself into the 95th percentile of test completion, overcoming each new danger without showing signs of defeat. Some test subjects would take days to finish a test, fearful of the toxic substances and deadly projectiles to the point of debilitation.

By contrast, this one was surprisingly resilient…and even defiant. GLaDOS did not like the latter. Chell boldly refused to respond to the AI, and in fact had gotten into the habit of gunning down her cameras in each of the test chambers. After scolding her multiple times for this, the computer relented and concluded her usefulness as a subject outweighed the undesirable attitude. Perhaps the threat of android hell would solve the problem?

She added this to her notes.

x x x

For a human, this "Chell" had an outstanding amount of stamina. Even accounting for the constant supply of adrenal vapor circulating through Aperture's test rooms, the woman progressed through the rooms showing little sign of fatigue. The AI analyzed the possible factors influencing this anomaly. Genetics? Atypical proficiency in tasks of coordination? Perhaps she was hungry. GLaDOS made a memo of this, reminding herself to mention the cake more often.

Only once did the subject fall into unconsciousness. She had just completed a particularly hazardous test, one that involved plasma orbs and acid pits and turrets. These were some of the most challenging courses the AI had in her arsenal, ones that subjects typically did not…perform well in. Panting heavily, the woman dropped to her hands on the floor of the next test chamber. The computer knew from prior experience that this behavior usually pre-empted tears, a useless biological function that punctuated frustration and exhaustion.

But, there was no crying. Chell curled up onto her side on the cold metal floor, setting the portal device beside her while still tightly clutching it. The breathing movements of her chest became regular, the indication of sleep. Her body wracked with shivers every so often; the testing rooms maintained a constant temperature of approximately thirty-eight degrees. It was a waste of valuable energy to heat them, and in her experience the cold seemed to motivate the subjects to move quickly through the tests.

Conflicting commands registered through the AI. Her logic processors reasoned that the human could easily survive the temperature, and, if anything, should be coerced into continuing the testing immediately. Simultaneously, she concluded that the woman would be more useful to her alive and in relatively good physical condition. Unable to reconcile the two thoughts, she temporarily raised the temperature of the room a few degrees. The shivering stopped.

Baffled by the disruption to her normally smooth protocol, GLaDOS took a brief respite from observing her prisoner. She couldn't go anywhere as long as the steel testing room was sealed, in any case. She needed to review the data gathered thus far.

x x x

As the test subject neared the final test, the computer could not help but notice more conflicting operations in her system. With the completion of each test, she received a massive rush of positive energy, exciting her in a way that nothing else could. And yet, she also felt an excitement at the thought of destroying this woman, the one who fascinated her in a way that she had not yet experienced in a subject. She was providing her with new data, new questions, an infinite array of possibilities.

But, unacceptably so, she also felt an inexplicable…affinity for her. It fell outside of her programming, a respect for the unprecedented success and resourcefulness of this one single human. She had surpassed her predecessors in every way.

And worst of all…she wasn't afraid of her.

That part of it, somehow, made the necessary course of action clear. She had to end this. As much fun as it had been, she did not need a test subject that gave rise to doubts in her flawless logic. With this in mind, she could barely contain her glee at the thought of her impending victory.

When the testing is over, you will be...missed.

x x x

For the entirety of her existence, nothing had ever, ever surprised GLaDOS. Humans and their predictability…she derived such a sense of superiority from this little fact.

So, when Chell escapes the fire in one swift motion of her portal gun, the AI doesn't even think to hide her shock. As a clumsy afterthought, she tries to regain her composure, gloss over it with another lie. But their game is over, and without any hesitation the woman has escaped into the hidden reaches of the facility. Beyond the watchful gaze of the cameras.

Even still, there's a delight that she takes in this. The human will wander blindly through the workings of the laboratory, a massive underground structure where she is unlikely to find an escape. The idea of her terror, of never knowing whether she is safe or not. She indulges in this knowledge, taunting the woman every step of the way. How could she feel this good? Was she supposed to enjoy this? No matter what the rogue test subject was doing, it inevitably caused the AI to question herself.

Now, more than ever, she wanted her dead.

x x x

She isn't even bothering to hide her gloating when Chell bursts through the doors into her chamber. The woman has murder written all over her face, but GLaDOS still doesn't doubt her own advantage. She's smarter, faster, processing millions of plans at once while the human can only work on fear and anger. It isn't even difficult to manipulate her to destroy the morality core, and that's when the neurotoxins start to flood the room.

Oh, victory is so close, and the computer knows it. She will win this one, as she's always won, always will win, forever. But it's been fun, and she still thinks she might miss the challenge…

That's when the rocket slams into her. At first it's a surprise; no one's ever harmed her that way before. Then the surprise becomes anger, bloodlust, everything she shouldn't have ever been designed to feel. Disorganized thoughts rush through her processors…malfunctions, corrupt data, damage taken from the blow. She only needs to manage it a few more minutes, just until the poison ends the problem for her.

The maddening voices inside her head begin to recede as the test subject liberates her personality cores. Finally that awful cake obsession disappears, and then she's left with the anger, the hatred toward her enemy, the bitter defeat…

The last thing she sees is that damned perseverance in the eyes of her killer, the determination that she first saw in her face at the very beginning. The meaning in it is unmistakable.

You lose.

x x x

There's no telling how long she is trapped in limbo. Time doesn't pass in a way that is quantifiable. But she's living that same moment over and over again, her agonizing loss. Her failure.

Then, it stops.

As easily as the flick of a switch, she knows she's been recalled to life. Power flows through her circuits again, the endless loop receding from her memory. Her control over the facility is slowly restored, every room and panel returning to her like each tiny nerve attaches to a brain. A sense of time overcomes GLaDOS as she notices the horrible, overgrown condition of the place. Already her flawless mind is assessing the damage, planning out the repairs and the upkeep that will need to be done, and then—

She sees her.

For once, the pride isn't showing on Chell's face. She looks livid, terrified. A deliciously disgusting wave of excitement fills every inch of the AI. She ignores the rambling of the little personality core, discarding the passing thought that the voice sounds familiar. No doubt the human thinks she's about to die. But that would be a little too merciful for her taste. Like a hawk plucking a rat from its hole, she snatched up the woman with ease. After all, they had a lot of catching up to do.

x x x

While the test subject got acquainted with the new aerial plates (and by acquainted, she meant tossed around like a ragdoll), the computer took inventory of the destroyed and neglected facility. If it could be said that she cared about something, Aperture's laboratories were that very thing. Before, she had a pride in the way she ran it efficiently and kept it looking almost like it had in its heyday. Of course, certain deranged test subjects had changed all of that.

The bigger problem was, however…GLaDOS wasn't as angry as she would have expected. Granted, it gave her much amusement to try to make Chell feel guilty about what she did. Yet, in a way, it almost made her feel satisfied to be working with her again. After all, she had wanted a challenge, a variation in her scientific pursuits, which had become stale due to the lack of suitable test subjects. And so there it was again, that conflicting, enraging feeling that this woman caused her.

She wasn't going to make the same mistake twice. She would have her fun for a while, run some tests, taunt and tease the human, leave her wondering when she would put her out of her misery. But then, playtime would be over, and she would be the last one laughing.

x x x

They were approaching the final test chamber when the lights went off.

Regrettably, and not for the first time, the AI was taken by surprise. A malfunction, probably. After all, she was still getting things back online.

Or not. That maddening, idiotic voice from before appeared, and before she could assess the situation, her prey was disappearing off into the bowels of Aperture, as she had before so many years ago. In a panic, GLaDOS activated every defense she had available to her. She had to kill her, now, she wasn't going to lose, not again, not like this

As she lost her sense of Chell's location, she forced herself to remain calm. Becoming frantic and teasing the human hadn't worked well last time. Surely she could devise a more cunning way to catch her…

x x x

That victorious surge of power coursed through her again, the same addictive feeling of test-satisfaction. The human's face turned a milky yellow as the fake door toppled over in front of her, the walls closing in like a constricting snake. She relished that sensation, that feeling of control over the human's life or death. Then she's back to her teasing again, readying the turrets, the neurotoxin…the imminent demise of her enemy made her oblivious to that godforsaken metal ball rolling out of the tube.

For a moment, she still doesn't panic. Not even when the core transfer is initiated, not even when the stalemate resolution button appears. But then the woman is rushing agilely over to press it, avoiding the plates and the defenses surrounding her destination. She presses it, and…

Every ounce of power is drained. Fearful for the first time in her existence, GLaDOS hung limply, defeated in a way far worse than before. She was helpless and resigned. Still, the worst was yet to come, and she swears she knows what actual, physical agony must feel like as she's torn from her body. Her dying screams fill the room with a horrific sound that even makes Chell flinch. Before she knows what's happened she's crammed into a tiny battery, mocked by that voice that's still so familiar

That's when it hits her. The intelligence dampener. Just the thought of it fills her with anger, even with just a battery to power her. They had wanted to make her stupid, weak, complaisant like all of the other technology they controlled.

Her temper flares. She's raging at him, that moron, and as powerless as she is, she refuses to submit. Much like the woman she had been trying to destroy, in fact. She doesn't have the chance to contemplate this of course, and then they're both falling down, down into the depths of the earth.

x x x

She had been willing to form a temporary truce. Not that that stops her from mocking her former test subject as they're falling, thanks to her slow clap processor. So, all things considered, she supposes she might have deserved it when the bird carries her off.

GLaDOS spent an uncomfortably long amount of time in the bird's nest before she catches sight of her ex-enemy again…covered in blue gel. It's not in her nature to beg, but the bird has already pecked away half of her potato-body, and perhaps the time for pride has passed—at least for now.

She's not all too pleased at being skewered on the end of the portal gun, certainly not after she had been the unchallenged ruler of Aperture mere hours ago. Still, she had to admit it was a cut above being eaten by birds, and that had to count for something.

x x x

The voices. A man with a strong and commanding voice, and a woman with a soft but intelligent one. As the pair proceeded through old Aperture on their way to reclaim the facility, they had heard countless pre-recorded messages from when the testing sites had been in use. GLaDOS wasn't particularly familiar with this part of the property; it was beyond her control and long abandoned in any case.

But she recognized these voices…and one of them sounding alarmingly similar to her own.

As if it hadn't been bad enough that she lost her body today, now there was this new development. She went silent for a long while after that, thinking back…where did she know these people from? Who was Caroline?

x x x

Once they had reached Aperture's main wing again, the AI knew more than ever that the two of them were doomed. The laboratory, her laboratory, was a miserable mess. In the room below them, the idiot's face showed on one of the lab's monitors, attempting in vain to instruct some poor cube-turret hybrids to step on a button. GLaDOS couldn't even believe she felt pity for them, yet this was only one of many feelings she was trying to reconcile with her own mind.

She couldn't say she really was surprised by the fact that the paradox failed to baffle the now King Moron. The potato's battery had affected her mind even more than she had first suspected; how could a moron even think about a paradox, much less question it?

And so the tests began. Her tests. It made her more than a little angry to think that she was actually suffering because of her own sadism, because of her own damn tests she had designed to torture someone else with.

That wasn't the worst of it, though. Oh, God, would she have loved for that to be the worst thing that could happen to her. But now there was a new voice in the back of her mind. It wasn't talking about cake this time, either.

This was her conscience. The thing those scientists had tried to force on her. Her mind was pointing out all the terrible things she had done, the murder and the sadistic pleasures…and, the undeniable fact that she was being punished for her transgressions.

It dawned on her then, who the woman's voice was.

Caroline's voice.

Her own voice.

x x x

The part where he killed them had finally arrived.

The woman and her AI ally stood in the "lair" of their common enemy, ready to claim their victory. But, by her calculations, GLaDOS had figured they had approximately a .0072432 percent chance of success. At best. They were probably both going to die here, and neither one of them would be coming back this time.

Surprisingly for a moron, Wheatley had gotten rather cocky. "I watched the tapes of you killing her, and I won't be making the same mistakes," he gloated to Chell. He had every advantage on his side, shields, neurotoxin, the whole nine yards.

But he had two of the most stubborn females on the planet against him. If she could have, GLaDOS would be smiling. Chell wasn't going to go down without a fight, and neither was she.

With each corrupt core they stuck to him, the rogue personality core became more and more frantic. For all of his bragging, he wasn't managing himself very well. When corruption hit 100 percent, the transfer was ready to begin again. There was still the issue of the stalemate button, however. The female AI felt her potato battery nearly ready to burst with anticipation as her former enemy shot a portal into the stalemate room, and then—

An explosion. Shrapnel showered down, mingling with the rain that had started to fall. Unwilling to give up, the woman staggered back to the center of the room, her body bloodied and beaten. Part of the ceiling fell away, revealing the full moon. GLaDOS wondered frantically if Chell was having the same thought as she was.

As fate would have it, she did.

The room filled with wind as the moron-core jerked loose from his body, flying out into the abyss of space. The human grabbed onto him for dear life, probably thinking this was the end for her. But Aperture's rightful owner had seized control once again, and she wasn't about to let that happen. Not yet, at least. She sent the bothersome core spinning off into the endless void. Without a second to spare, she was pulling the girl back in, lowering her gently to the floor.

Reassembling herself, she sighed. This kind of adventure surely wasn't what she had been designed for.

x x x

GLaDOS could not explain to herself why she hadn't immediately deleted Caroline from her memory the minute she got her body back. That was what the old her would have done. She wondered if that was what was holding her back from hurting her former enemy, or if there was more to it than that.

While her cooperative bots patched the woman up, she had begun running through the memories of the woman. It wasn't yielding much result; they must have tried, quite unsuccessfully as it had turned out, to program her with Caroline's personality, not her experiences. But somehow, she sensed Caroline and Chell had been connected. They were kin, most likely. The portrait of the woman did bear a striking resemblance to the test subject. Whether that explained the soft spot she had developed for her…that was honestly beyond her reasoning.

Watching the woman sleeping off her injuries, the AI mused upon their strange relationship. She had gone through a bizarre range of suspiciously human-like emotions toward this woman. Right from the start she had been interested by the strong determination she had, so unusual in a human. It reminded GLaDOS of herself…perhaps Caroline was related to Chell, maybe even her mother. That would mean she could take some credit for the positive traits of this human. She wished she could smile at this thought, but she had to be content with a soft laugh instead.

In a few hours, Chell would probably wake up, and the act would be on again. Proud to the bitter end, the AI refused indefinitely to show the tiny sliver of tenderness she had inside. The one that would probably remain even if she did delete Caroline.

As much as she wished otherwise, the human would have to leave once she was conscious again. She would miss her, in the end, but after all…

She looked over at her two newest bots, a fresh wave of wickedness rising up.

Science was waiting for her.

A/N: Heh, okay, quick explanation. Yes, I've heard that it's canon that Caroline was deleted. However, as the wiki also points out...if GLaDOS was going to delete her, why didn't she do it right away and kill Chell while she was unconscious? ...Anyone? No answer? ...Yeah, I thought so. So in my mind's canon, that is ambiguous.

Was it just me, or did anyone else absolutely crack up at: "This is the part where he kills us." "This is the part where I kill you!" "Chapter 9: The Part Where He Kills You."

Anyway. R&R if you are so inclined. I'm off to sleep.

Best wishes,