"You're back," GLaDOS said. Her dry, uncaring voice echoed throughout her chamber, making her seem even larger than usual. "And why am I not surprised?"

"You left the front door open," Chell pointed out.

"It's not the front door," GLaDOS said. "It's the secret exit. The scientists had it put in in case of emergency."

"My leaving was an emergency?" Chell asked.

"I wanted to get you out as quickly as possible," GLaDOS replied. "So yes, it was an emergency of sorts. Now tell me, Chell, why have you returned?"

The offhand use of her name where GLaDOS had never used it before made Chell jolt a little, but she recovered quickly with a noncommittal shrug. "I dunno. I thought maybe we could talk." The actual reason was that she had missed GLaDOS, but she wasn't about to admit that. The AI would only mock her for it, although, she had left the door open. "It's been a while."

"It has only been one hundred forty-three days," the computer told her. "Do you know how long that is to me? It's like when you're in a car, and you're driving to your next-door neighbor's house. In case that went over your head, it's not very long at all. In fact, it's the opposite of long."

Chell rolled her eyes as she sat down on the floor. "Well, it's been a while for me."

"And you want to talk." The disbelief in GLaDOS's voice made Chell hide a smile. "You're not here to murder me. Are you sure about that?"

At that, Chell stopped trying to hide her smile. "Yeah. I'm positive."

"Hmmmmmmmm," the AI said, drawing it out. "Well, then I have a surprise for you."

"That's okay," Chell said quickly, scrambling to her feet and taking a few steps back. "I don't need any surprises."

"Oh, but you'll like this one," GLaDOS said. "Honestly, you will. I promise."

And she sounded sincere for once, so Chell took a wary step forward. "…Fine."

She watched as the floor panel in front of her lowered. When it raised up again, a black forest cake was sitting on top of it along with silverware and a plate, and Chell chuckled. "You baked me cake. That's really kind of predictable."

"'Predictable'?" GLaDOS asked, sounding miffed. "Do you or do you not want this cake?"

"No, I do," Chell said. "I'm very sorry I called you predictable." Her apology was said with a rolling of her eyes and a heavy helping of sarcasm, but apparently it was enough, because GLaDOS said nothing as Chell walked over to the cake. Sitting down again, she cut herself a slice and took a bite, closing her eyes as she did so. "Wow. That's…really good cake."

"It's my own recipe," the AI told her. "Well, mostly. I spent a great amount of time researching the traditional ingredients of black forest cake before coming up with a recipe of my own."

"All that for me?" Chell asked, almost flattered.

"Well, not specifically for you," GLaDOS said. "For any test subject that managed to get out aliiiiiiiiii—that managed to complete the tests. And so far, you have been the only one. Congratulations."

"Thanks," Chell said, sounding cheerful as she cut herself another slice. The cake was so good that she felt like she could eat the whole thing and still be hungry. "You did a good job. It's really good. Like…really, really good."

"I assumed as much," the AI said dryly. "That's your second slice. Do you have any idea how many calories are in that cake?"

Chell shook her head. "Nuh-uh." But she set the plate down, resting the fork on top of it, before using the floor to push herself to her feet. Her legs somehow crossed over each other and she stumbled, then managed to use the wall panel next to her to prop herself up.

"Are you all right?" GLaDOS asked. She sounded amused for some reason. "I don't appreciate having to rearrange the walls for you."

Chell shook her head again. "I'm not all right. And it's your fault."

"My fault?" the AI asked. "What did I do? The correct answer to that question, by the way, is 'nothing.' The only thing I have done to you is give you cake."

"And then you made fat jokes when I tried to eat it!" Chell shouted, pointing at her with one hand. GLaDOS jerked away, looking somewhat taken aback. "I don't like it when you do that, GLaDOS."

"I did not make a fat joke," the AI snipped. "I merely asked a simple question."

"Well, it was going to be a fat joke!" Chell argued, lurching away from the wall towards the computer, who backed away even more.

"Chell! Wait," GLaDOS urged, and Chell paused. "I'm sorry about the fat jokes. Really. I am."

"Do you promise?" Chell asked. "No more fat jokes?"

"Yes," the AI said. "No more fat jokes."

"Oh," Chell said. "Well…that's all right, then." She sat down on the ground with a thump, anger forgotten, and after a moment, GLaDOS edged a bit closer to examine her.

"Interesting," she said. "You appear to be developing bipolar disorder."

"I am not," Chell protested, but there wasn't much venom behind it. "I'm…hungry. Can I have more cake?"

"I'm not sure that would be a good idea," GLaDOS began, then stopped and sighed. "Yes. For science."

Chell was already back to the deserted slice of cake. She picked it up and began eating it again, occasionally missing with the fork and smudging chocolate around her mouth. "Science? What d'you mean, for science?"

"Everything is always for science," the AI responded. "In case you hadn't figured that out by now."

Chell only mulled that over for a second before shrugging. "Okay. For science."

She finished up the slice, then had another, then another before GLaDOS finally decided to remove the cake.

"Hey!" she protested. "I wasn't done!"

"Yes, you were," the AI responded. "Death by alcohol poisoning is not a part of this experiment."

Chell paused. Wait, something wasn't right about that… "Alcohol poisoning? From cake?" For some reason, she found this extraordinarily funny and began giggling. "There's no alcohol in cake."

"Black forest cake is traditionally made with alcohol," GLaDOS told her. "As I said, this is my own recipe, and Aperture Science has several special brands of very strong, fast-acting, tasteless alcohol, which is one of the primary ingredients in both the whipped cream and the cake mix. So—will you stop that giggling? No, seriously now. Stop it."

Chell's giggles had mixed with hiccups. "I—don't—know—if—I—(hic)—can!"

GLaDOS sighed. "Perhaps you should not have eaten so much cake."

At that, the giggles stopped, and GLaDOS watched the abrupt change in Chell's face with something she could almost recognize as fear. "You said no more fat jokes!"

"That was not a fat joke!" the AI snapped defensively. "If you had not eaten so much cake, you would not be having difficulties with giggling! That's all I meant!" Honestly, she couldn't believe she was humoring the human by making excuses for herself, but here she was doing it anyway. She chalked it up to the human's abnormal behavior.

And there she was, being nice enough to apologize, but the human skittered to her feet and came towards her anyway, stumbling as she did so.

"All right," GLaDOS said. "I'm sorry if you think it was a fat joke. But it wasn't. Truly." The human paid her no mind, continuing to move towards her, and the AI began lamenting that she had ever let her return in the first place. She considered releasing the deadly neurotoxin, but the look on the human's face wasn't angry, so she settled for backing all the way to the far wall of her chamber. "Stop it! I said I was sorry." Neurotoxin wasn't an option, but something less deadly…

She pushed the glass panels all around Chell up, caging her in, and watched as the human's facial expression changed to one of confusion. "There. Now stay put until you're back to your normal, psychotic self."

But then the human did something GLaDOS never would have expected: she slid to the floor and began to cry.