A/N: I got this idea like waaay back when, and a reviewer mentioned the same thing to me which I found amusing, so after a month or so I've finally brought myself to write it out.

Cover art is courtesy TwinklePowderySnow at Deviantart. Big thanks again to her for the lovely fanart, I'm flattered to this very day. :)

Disclaimer: Portal is (C) Valve, who needs to make a super-awesome line of Portal action figures. With kung-fu grip.

x x x

As much as she had known the moment would come, there was no way she could have predicted what it would actually feel like to see her favorite test subject walk through the door…with an extra visitor in tow.

It seemed so terribly soon, and perhaps it truly was. GLaDOS knew she would live a long, long time, and that a matter of months, years, decades, passed in an instant. Time, like most things, was relative. A short time to her, however, equaled a lifetime for a human.

Her human was no different, unfortunately.

These thoughts had all occurred to her before, many times, and so here they popped again as she watched Chell moving toward her with a small hand clasped in her own.

"I hope you don't mind extra company today," the woman laughed lightly, her tone as playfully sarcastic as ever. "I just figured it was about time for Lia to see the family legacy. You know, get used to the insanity before she's old enough to know better."

One hand gripping her mother's pants leg, the little girl hid shyly behind Chell. This, along with the dark lighting, made her a bit difficult to size up. GLaDOS noted long brown hair, just like her mother, and just like…

"By 'legacy,' I really do hope you mean the facility." The AI came slightly forward, though with some degree of caution. As if she needed more frightened little girls added to her record. "…and not me," she added dryly.

Hearing the loud, unfamiliar voice, the child peeked out from the safety of her mother's back. Unsurprisingly, she didn't seem to be exactly afraid. That tended to run in the family.

"Well duh, of course. I meant Aperture in general. I consider you a who, not a what, in case you didn't know that already." Chell smiled warmly. Snippy dialogue was their language of affection, after all. "Still, she's not going anywhere near the rest of the place yet. God knows it isn't childproofed."

"But Bring Your Daughter To Work Day is the perfect time to have her tested…" Not entirely meaning to, GLaDOS spoke the old phrase with a certain languid tone, like she wanted to disown it. The unspoken cue hit a range of emotions that could only be understood between the two of them.

"This time is different, though," she answered gently. Subconsciously, she ruffled her daughter's hair fondly. "In fact, I had an extra special favor to ask of you."

"Not babysitting, I hope. I don't anticipate your mate would consent to that." She lowered her head in amusement. "Or the child even being here in the first place."

"And that's exactly why Dave doesn't know about this." Chell grinned at the thought, her eyes showing that irreverence again. "He thinks she came to work with Mommy today. But some secrets need to be kept inside the family. Especially secrets as crazy as this one...not to mention, you'd make one hell of a scary mother-in-law."

At this, GLaDOS chuckled deviously. "Don't worry. I'm not expecting an invitation to Thanksgiving dinner any time soon."

"Actually, the favor is a little bit bigger than babysitting, to be honest." The woman glanced off to the side, clearly a bit uncomfortable with approaching the topic. "…I wanted to ask you if you would be her godmother."

A familiar silence filled the room, made more apparent by the ever-present mechanical humming. The computer drew herself up slightly out of uneasiness. "As in a religious sponsor?" she responded slowly. "I don't quite follow."

Chell shook her head. "No, I mean as in a guardian. I want Lia to have someone who promises to watch over her, and care for her in case something ever happened to her parents."

She had already made that promise to someone else, GLaDOS thought dryly. Now Caroline's daughter was asking the very same thing. Humans really were too predictable for their own good.

And still, she just couldn't come out and say no. Maybe she was becoming just as bad as they were after all.

"So what made you come to me for this particular favor?" It was a genuine question, and they both knew it. "Because your mother is in here with me?"

A sour little note of jealousy lurked in her words. For GLaDOS, there would always be some resentment toward Caroline, the woman that Aperture had been hoping she would be an exact replica of. They had been so sure it would work that they even designed her speech to sound the same. But that was where the similarities ended. The idiots who created her were completely oblivious to the fact that she came into existence with a personality all of her own.

Indeed, she wasn't like Caroline at all. But it seemed that everyone had wanted her to be. Was it a crime, GLaDOS thought spitefully, to be your own individual?

"No, that's not it." Chell sighed, a little bit of hurt passing through her expression. "I know you and Caroline are two different people. Believe me, that much is obvious. The reason I'm asking you is because I trust you, and I consider you part of my family."

"Family," the AI stated blandly. "Humans consider family to be the ones who share their immediate genetic origins. I'm not a human. I never was, and I never could be."

"That is not true. Family is whoever cares about you and you care about them." She paused. It wasn't like Chell to struggle with words, but being sentimental with GLaDOS tended to have its challenges. "You're like a mother to me, after all. A really harsh and negligent mother sometimes, but the fact still stands. I felt like that before you told me about Caroline being my mother, so you can't use that excuse on me anymore."

GLaDOS shifted her position slightly. "Oh, is that so?"

"It sure is." Chell wasn't backing down on this one, to no one's surprise. "You may be fooling yourself, but not me. I know that voice of a conscience inside you is yours. Not Caroline's, or a personality core. God knows you never listen to anyone but yourself. So when I came here today with this request, it's because I do know you and for some reason that still eludes me, I do trust you."

The AI stared intently at her, her gaze as calculating as it always had been. When she spoke, it was a statement, not an inquiry. "Enough to trust me with your child."

Chell smiled, the sincerity evident in the simple expression. "It's cosmically wrong, but yeah. I do."

She glanced down at her daughter, who was still holding tightly to her hand. Her big brown eyes were taking in everything, but rather than fear she showed a bold curiosity. So typical. Chell bent down to pick her up, a new smile growing at the sight of her child.

"I've got someone for you to meet, Lia," she told her gently. "She's big and scary sometimes, but I think you two should meet."

The woman came in closer, careful not to startle the little one. GLaDOS guessed the child must be no more than three or four, though size wasn't always the best indicator of age with girls. The AI remained still, not quite sure how to respond to this situation. She had never met such a young human, and most of her knowledge on them was purely factual. Lia held her arms tight around her mother's neck, peering out at the strange thing with the big voice.

Chell laughed quietly at the two of them. They were equally curious of each other, as it would turn out.

"Can I…" GLaDOS began, trailing off. It wasn't quite like her to be uncertain…but this wasn't science. "Can I see her?"

Motherly instinct had her guard raised a bit, but Chell smiled in permission. "Go right ahead."

Very gradually, the intimidating machine moved in to examine the girl. She stopped short when they were at eye level, only a matter of inches between them. The child looked up at her mother questioningly.

She stroked her daughter's hair reassuringly. "It's okay, honey. You can say 'hi' to your auntie, okay?"

The little girl hesitated for a moment, but after only a short minute she reached a tiny hand out to touch the computer right below her glowing optic. Her voice was small and shy, but GLaDOS could clearly make out, "Hi."

The AI stayed perfectly motionless, the tiniest bit annoyed with herself for the intense emotion that was welling up in her system. She cursed her own feminine nature, anything that could make her feel this joy and protectiveness over a child. Maybe she should delete that too.

Oh, but that would never happen. The feeling was just too wonderful, like the testing euphoria multiplied a thousandfold.

Chell watched the two of them with a wry smile on her face. She was pretty sure she had won this round, too. "So what's the verdict? Is it a yes?"

Somewhere inside her memory, Caroline was beside herself with laughter.

You better knock that off, or it's a one way ticket to the Recycle Bin for you, GLaDOS warned her flatly.

As much as it murdered her pride, the AI nodded just the tiniest bit. She didn't think she would ever figure out how they did it, but these humans had her wrapped around their finger.