Portal 3

Prologue

Virgil
In the deepest, dankest depths of Aperture, a lone artificially intelligent sphere used an old trick. He detached from his ceiling railing, and activated antigravity software before hitting the floor. He hovered, able to control his movement to reach the side wall. Next, he used and extension of his antigravity to knock twice on a panel within the wall. The panel flipped down, letting a partly melted Aperture Science Quantum Tunnelling Device - or more commonly called a portal gun. He used his antigravity to hold the portal gun, one from the seventies, just like him, and held it as a human would. Now, he could aim and fire portals however he needed.

For any spectators whom do not understand the significance of these portals and their use, read this short explanation. There are two portals, which are linked, like two sides of a door. However, they are able to be opened onto different places, meaning that one can travel through to, say, avoid falling into toxic goo. They can also be used to propel objects and/or people. It's a little mind blowing, but this might be the simplest understanding. The proper terminology might be Internally Linked Portals - meaning that they cannot travel between separate dimensions.

Anyways, the sphere admired the portal gun now in his possession, "Sorry Mel... I didn't tell you that this furnace only goes up to three thousand, nine hundred and ninety nine degrees Kelvin." He slowly moved the inner panel of his face from side to side, the way his machine kind shake their head. "And it looks like the paper clip, er, melted... a bit."

Now, he knew what he had to do.

Although he didn't know how long it took him, the sphere called Virgil headed towards the Central AI's lair. The Central AI acted as Aperture Science's CEO, and leader of the various machines which lived here. However, after the fall of an old criminal to the machines, the current leader became despotic, violent, sadistic and vengeful - tyrannical. There was an upstart Central AI which didn't last too long, and maybe for the greater good, since he quickly became frightfully corrupt under the influence of power. He was swiftly replaced by the former AI. Alas, now it seemed that the current AI was becoming worse than the upstart. It was he whom Virgil was interested in, regarding the current location of him.

To dodge the creepy little turret patrols, Virgil silently went through portals towards the lair. Outside the corridor along the emptied area separating the lair from the rest of the facility, he spied her cameras. They scanned the area intently, warning her of anything's approach. Then, he shot a portal behind the two cameras, forcing them all the wall and crashing into the floor. Now she'll know I'm coming, Swiftly, he charged down the bridge to the door before the lair, and tucked himself into the walls beside it. Slowly, the heavy door slid open, and he peered in before floating in.

The Central AI - Genetic Life and Disk Operating System - was facing away, her massive bulk fixed to the ceiling permanently. Quickly, she sensed his presence, swivelled around and glared at him with her sickening yellow eye. Upon seeing him, she chortled with a mechanical laugh, "Another sphere come to try to take my place?"
"Where's Wheatley?!" Virgil demanded, knowing her question was merely a sneer.
GLaDOS pulled her head back, feigning confusion, "...Who?" From the base below her, a metal claw slipped out and flew in Virgil's direction. Quickly, he held the portal gun in front of him, blocking the attack with a loud CLANG.
"I know he's been here, somehow!" Virgil demanded again, "Where is he?!"
"I don't know who you're talking about!" Lied GLaDOS, pulling her claw back and preparing to slash, "Why don't you tell me how I happen to have a security system that's shutdown and tried to murder me!"
"Uh... that, um, that was me," Virgil admitted, cautiously angling his portal gun to block her next move, "A human and I were targeted too. Tried to flood the place with that toxic goo."
"That AEGIS... you're sure neither of you told him to target me?"
"What? No!" Said Virgil, then looked towards the claw as it came slashing and blocked. "We didn't have control of his targeting! I told you already, he targeted us."