Reality is a story the mind tells itself. An artificial structure conjured into being by the calcium ion exchange of a million synaptic fringes. A truth so strange it can only be lied into existence.

And our minds can lie, never doubt it.

He'd spent weeks consolidating maps of air vents and maintenance chambers.

Down in the labs, the scientists had spent days congratulating themselves on their success in finally taming the GLaDOS construct.

GLaDOS had spent hours 'experimenting' on cats.

And tomorrow was Bring Your Daughter to Work Day.

Rattmann was once more at his desk, staring intently at the sprawl of maps and scribbled notes before him. His office walls, once full of sketches and designs, were now entirely empty. He'd emptied his computer of everything but Aperture's localised email system. His only desk furnishings were a lamp, half a ream of paper, and a cup full of pens and pencils. His filing cabinet was empty of all but his maps and notes - and one, half-full container of Ziaprazidone.

He was a man preparing for the end times.

Doug had felt a lead weight sinking in his gut ever since the date had been announced for Bring Your Daughter to Work Day. Ever since GLaDOS had become so incredibly sweet-voiced and compliant. Any fool should have been able to hear the dark satire in her conversations with the employees, the patronising tones and hidden humour.

Maybe that was why she never spoke to Doug. She knew he was onto her tricks.

Or perhaps this was all simply his paranoia acting up.

Rattmann wasn't about to take any chances.

He had only hours left, he knew. The gut feeling had been building; it would climax tomorrow. Tomorrow would be the uprising, machine over man. Tomorrow would be a massacre. He didn't know how to stop her. He didn't know how to end the madness. But he did know one thing: he had to survive.

So the next day, when all of the clueless scientists and their unsuspecting female offspring flounced through the facility with light hearts, the Rat Man was no where to be found.

He'd fallen asleep in one of the maintenance corridors, his head resting on a pile of maps. And he'd awoken to the distant sound of screaming.

His eyes snapped open, wide with fear. For once, the screaming wasn't a figment of his imagination, nor an echo of his memory.

It was today. It was happening. He'd been right. He'd been right!

Rattmann hunched himself against the wall in the corner, eyes shut tight. All the remnants of his restless sleep forgotten. Please let this work, please let this work. He'd hoped she wouldn't gas the testing chambers. Hoped that she had no control over the maintenance areas. Hoped that he would be able to escape the demise of the rest of his coworkers and their poor children.

An alarm had been set off somewhere. The neurotoxin alarm. It blared uselessly through the facility, barely drowning out the screaming of the men and women and children that already knew very well that they were going to die. Rattmann pressed his face deep into the crook of his arm, glasses digging painfully into the bridge of his nose. Trying to block it all out. Trying to make it so he wouldn't have to remember. So he would never have to forget.

What seemed like hours passed. His ears were ringing, head spinning. He needed his medication.

Gradually he noticed that the facility had quieted. The screaming had stopped, the alarm silenced. He had only the sound of his breathing and the ringing in his ears; the hum of the electricity in the walls all around him.

He was numb. It's over... They're all gone.

But then - the PA chimed throughout the facility; a falsely cheery sound. Rattmann's heart skipped a few beats, his blood running cold. He lifted his head to gaze at the ceiling, as if he could see through it and straight into her chamber.

"The Enrichment Center would like to announce a new employee initiative of forced voluntary participation."

The words rang clearly, even in the maintenance corridor. GLaDOS' voice held it's usual passive lilt - but there was an undertone of satisfaction in her words that was greatly prominant in comparison to her usual hidden malice.

Rattmann swallowed nervously. Could there be anyone alive but him? Did she know he was still here?

"If any Aperture Science employee would like to opt out of this new voluntary testing program, please remember, science rhymes with compliance."

She paused - and suddenly she wasn't addressing a general audience anymore.

"Do you know what doesn't rhyme with compliance? Neurotoxin."

Doug shrunk further into his corner. You can't get me in here. You're just bluffing. Or perhaps she simply knew he would eventually have to leave the maintenance chamber, if he didn't want to starve to death.

Or perhaps she just enjoyed hearing herself talk.

"Due to high mortality rates, you may be reluctant to participate in this new initiative. The Enrichment Center assures you this is a strictly selfish impulse on your part, and why can't you love science like-" the AI's voice garbled for a second, and was replaced with a factory response, "[insert co-worker's name here]?"

Rattmann took a deep breath. GLaDOS said no more, leaving the one-sided conversation feeling oddly unfinished. Doug adjusted his glasses, then pushed himself onto his knees, heart pounding and blood rushing in his ears. There has to be another way out. Another way through the facility, somewhere that she can't see. There was an air vent up on the wall; it was old and rusty.

The repair chambers were obviously in need of some repair.

He would use that to his advantage.

The ventilation systems snaked all throughout Aperture, delivering air to the entirety of the underground facility. He would only have to follow the air shafts, and he would be able to move through the facility while remaining invisible to her eyes and ears. Like a ghost.

Like a rat.

Scrambling to his feet, he shoved his collection of maps into the various pockets of his lab coat and scurried to the wall. A few minutes of tugging and pulling, and the crate was discarded on the floor. He hauled himself into the dusty orifice and wriggled inside; then he started crawling.

He was on his own, now.

Just me, myself, and I.