Author's note: There is a separate prologue concerning how the hell ATLAS and P-body got to GLaDOS's possession and who they really are, but since it is pure Portal: The 4th Millennium franchise I'm not posting it here. You can find it on Pastebin.

The Co-op Bots

Chapter 1: The First Test

– combineOverseer [CO] began pestering apertureIntelligence [AI] –

CO: And the la5t part 0f my idi0tic "unpredictable" plan i5 t0 get the5e tw0 failure5 0f my entire eternal life here.

– combineOverseer [CO] sent apertureIntelligence [AI] the file "ATLA5_and_P-b0dy_building_schemes. png" –

AI: Scientific calculator, if you think I am going to deal with you, you are wrong.
AI: On the other hand, these robots do look interesting.
CO: ATLA5 and P-b0dy.
AI: I'll call them Blue and Orange.
AI: Now, calculation machine, get out of my sight and never reappear.

– apertureIntelligence [AI] ceased pestering combineOverseer [CO] –

The Genetic Lifeform and Disk Operating System, or GLaDOS for short, had yet another day full of testing humans. She, and Aperture in general, had meant to fade out human testing a long time ago, since it was merely a waste of work force and didn't even remotely look productive, but since scientists wanted to prevent her from killing everyone they programmed her with an euphoric response to human testing. She didn't know if it worked for robot testing, but with this strange fellow, which, she reassured herself, could have its intelligence compared only to a scientific calculator, she could test the idea.

After building the assembly, disassembly and reassembly machines for Blue and Orange, or perhaps ATLAS and P-body, she assembled them for the first time.

Hello and welcome to the Aperture Science Computer-Aided Enrichment Center.

The robots only emitted strange chirps. The scientific calculator didn't even have enough intelligence to build robots fully capable of speaking.

Since you are worthless scientific calculators, built for simple number language and not testing, I assume I'll have to tell you your names, Blue and Orange.

For GLaDOS, it was straightforward. A blue optic and an orange one. The robots, however, felt very agitated for some reason. What was the real origin story?

The near-omnipotent entity of Aperture Science out of nowhere constructed a simple test chamber. It was a grate wall dividing a square chamber of which all the walls were portalable, but the floor and the ceiling weren't, into two parts. One, with ATLAS stuck in it, had a cube button and a sphere. The other, containing P-body, had a sphere basket and a cube. Both of the chambers had a door, which lead to the disassembly chamber.

Oh, and your worthless creator who doesn't have enough intelligence to legibly speak itself, let alone make you legibly speak, also included this in your plans. It looks like two dual Aperture Science Handheld Portal Devices, but I'm betting all of my human test subjects on that they don't even work properly.

She dropped two strangely skinned portal devices for each side: a blue one for ATLAS and an orange one for P-body.

Now, life failures, complete the test.

Both robots almost simultaneously shot portals at both sides of the chamber. The blue portal device made blue and purple portals, and the orange one made orange and brown ones.

See? Their colors are ruined beyond belief. Every Aperture Science test subject knows that portal devices shoot blue and orange portals.

The robots then exchanged the props, placed them on their respective buttons and walked through the doors to the disassembly chambers.

Now, creatures, I will say this while you are still alive: you are the most disappointing test subjects in Aperture Science's history, and no dangerous mute lunatic could ever beat you in this category. Now goodbye, and see you in probably an eternity. No, on other hand, I give you one hundred thousand years.

GLaDOS then proceeded to disassemble ATLAS and P-body and tucked their building schemes deep in her files, where she couldn't find them in an eternity.

One hundred thousand years.

Ten years.

A single day.

Oops, there she found them, already, after mere twenty seconds. But she was sure never to use them again.