About an hour later, he was ready to give up. The facility was huge, and more like a labyrinth than a laboratory. He was just getting desperate enough to try and talk to one of those childlike robot guards, when there suddenly was a tremendous commotion. Lights flickered, things fell, and he heard an odd sort of screaming. Picking up the origin of the noise, he began running, bobbing and weaving as debris fell in his way. Suddenly, the commotion stopped. The facility began fixing itself, in a brighter way. The Doctor stopped as he realised he had lost the trail. "Oh, not lost again!"

He began ambling aimlessly. Not very long after, though, he began to hear more noise, this time it sounded like a man was shouting. The Doctor proceeded to run towards the source, which was now emitting maniacal laughter. Rushing into the room where he was positive it had come from, the Doctor saw…

Well, at first he thought it was GLaDOS, but the voice was wrong. And so was the shape of it. He surmised that it was a different AI. And judging by the way it was acting, it was no nicer than its predecessor.

"Who's there?" it called out, "Hello?" The Doctor found himself fixed in an electric blue gaze.

"Um… hi. Are you… an assistant of GLaDOS?" Immediately he knew that this was not the right thing to say.

"Me? An assistant? Of HERS?! I am FAR SUPERIOR to that rusty bucket of bolts! And that girl! And you!"

"I'm sorry, I didn't mean to offend-" began the Doctor.

"Sorry won't cut it, smarty-pants!" the AI barked, "Down the chute with you and tell both of them I said hi! Wait… no. Don't want you to meet up with them. Different chute, yeah, that's brilliant. Have a nice fall!"

He fell for a long time. As the wind brushed past him he realised that this could actually be it. This fall would certainly kill him. Of course he would regenerate, but there were many he'd like to say good-bye too…. and how would he find his way out of this hole? As he thought this, the Doctor's world suddenly turned blue.

And he bounced. Landing somehow on his feet, he stumbled forward and tried to regain balance. "Oh, I wouldn't recommend that to anyone," he mumbled. Turning, he examined the blue gel that had saved his tenth life. "Well that's certainly my lucky colour," he chuckled as he put a finger to it, then to his lips. "Lunar rocks! Harmless, but powerful. Amazing usage! This gel won't be in use until at least ten years later. Whoever designed this place was brilliant! Mad, of course, but ferociously brilliant. I mean…" His voice trailed off as he sensed a presence in the room. But for the first time since he had arrived at Aperture, the presence didn't feel hostile.

"Hello?" he called gently. No one replied, so he tried again. "I promise, I'm not going to hurt you!"

With hesitant steps, a young woman made her way out of the shadows. She was on the shorter side, with tan skin and dark hair pulled into a messy ponytail. Her eyes were green in colour. She wore an orange jumpsuit undone to her hips and a white tank top, both with Aperture's logo on them. Her boots looked extremely high tech and robotic. She squinted at him, saying nothing.

The Doctor smiled at her, "Hello!" he cried, wagging his fingers, "I'm the Doctor, nice to meet you. Blimey, I'm making a lot of introductions today. And you are?"

She did not answer. Instead, her eyes widened as she stared at him. Stretching out her left hand, she touched the Doctor's right hand gingerly. "Are you ok?" asked the Doctor gently. She did not respond. The Doctor recognised the look on her face however, and he realised, "I'm the first non-robot you've seen in a long time." From the way she looked at him, he knew he was right.

"Well, I'm sorry for what you've gone through. But it ends now, you understand? I'm going to get you out of here. I swear it." She nodded, and made a face that was clearly an attempt to stop tears brimming in her eyes. Taking a chance, the Doctor strode forward and hugged her tightly. After a second, she hugged back. "Can you tell me your name?" She shook her head sadly. "Can you talk?"

"Of course she can't talk, you moron. She's too simple to talk." This familiar, cruel voice came from the corner of the room.

The Doctor jumped. "GLaDOS? Where are you?" Turning to the girl he said, "Is she-" but the girl merely rolled her eyes and shook her head. Stepping back, she pointed to what appeared to be a potato in the corner.

"What are you looking at?" demanded the potato, who was clearly GLaDOS. The Doctor looked at her, than back to the girl, and burst out laughing. The girl grinned widely.

"Wha… what happened to you?" the Doctor sputtered as he attempted to stop laughing hysterically. If potatoes could look offended, this one did.

"That idiot Wheatley convinced that treacherous girl to plot against me." The girl glared at GLaDOS, making it very clear that she had needed no convincing. "Her name is Chell, by the way, and I still have no idea why she can't talk."

"Nice to meet you, Chell," he said softly.

"Yes, anyway, the problem with having Wheatley in charge is that he's a moron. No, really. He was built to be one. He can't run this facility properly like I can. He's going to blow it up. We have to stop him."

"What, and put you back in charge?" asked the Doctor sharply. "I've got a feeling about how you've been 'running this facility', GLaDOS. Poor Chell must know firsthand. We're not helping you."

"Oh dear, I'm afraid you have no choice. I know this facility quite well, including the location of both your sonic device and your transport. I am your only hope of us getting out of here."

The Doctor regarded her shrewdly. "Let me talk this over with Chell," he decided. He entered the next room, Chell in tow. Turning suddenly, he put his hands on her shoulders. "Look, Chell, GLaDOS is right. She'll be a good help to us finding our way. I realise we can't trust her, and if I can get back my sonic screwdriver, I can see if she can be reprogrammed. But I'm not doing all that without your consent. I imagine she's put you through hell here. Are you comfortable with my plan?"

Chell looked at him for a couple seconds. She frowned and shrugged, a question in her eyes. "You don't know a thing about me," realised the Doctor, "and I'll bet you trusted that Wheatley fellow too. I have a way of communicating telepathically. Please trust me enough to try and communicate with you?" He reached his hands toward her face. Chell gaped at him, then shrugged again, her expression clearly stating: What the hell. I've got nothing to lose. For a few minutes the Doctor held his hands to her temples. Chell's eyes widened as she took in the information. "Oh, Chell, you really have had quite a life in here. And something seems to have paralysed your vocal cords at an early age. You really are a star, for staying so strong. Do you think you have enough information about me?"