Disclaimer: I don't own Doom or Black Rock Shooter.

Prologue:

Humanity

The future was far darker than we expected. Humanity is at war with an alien race for nineteen years. We've lost it bad. All governments and armies were wiped out of the face of the Earth and only a few humans have survived the slaughter, now Earth is a deserted wasteland, almost devoid of life, a shell of it's former glory. But we found our hope for the future after years fear: Subject Black Rock Shooter. Our finest soldier, our pillar of hope, humanity's final warrior, have finally awakened from her slumber. But even with her assistance, it isn't enough. The aliens still have the upper hand, and now they're closing on their objective of exterminating the last few of us. We've buried our hopes on the most profound darkness. But then a miracle, if you want to call that, happened. The mightiest warrior had woken up and shed light on Rock's past: Project ADAM. And he brought us out of the darkness.

Chapter 1

Rude Awakening

BGM: Aliens, Say Your Prayers!, By Bobby Prince.

Not too faraway from San Francisco, USA.

Military Underground Base, Codename: Genesis

Research Division Of Subject 2018-0, Stasis Section, Subject Containment Chamber.

Rebooting systems... All systems nominal. Base Lockdown ended. Initializing Chamber shutdown...

After the base warning and a load of steam and metallic sounds, the chamber opened and a man falled into the floor. A after sucession of moaning and sighing, he quickly stand up and looked around. It doesn't look like anything the UAC have built, since it looked much older and outdated, plus it looked like abandoned. No one enters this base for at least some years. But then something catches his attention from the other side of the room.

It was his armor. Quickly suiting up, after checking if everything was in the right place, he noted something: it appeared someone was desperately trying to do something with the armor, since there was a lot of tools (most of them broken after somekind of struggle, probaly trying to do something with the suit). Poor bastards. A note was in the floor, near the stand where the armor was displayed, that reads:

"We tried everything, General. The armor is impervious to any kind of damage and all of our tools, even the most advanced ones, they break like matchsticks. Damn, we tried even diamond drills and lasers! It appears the armor and the man are like two components of the same machine, one will not work without the other. I suggest we move on with the ADAM Progam or all hope will be..."

The rest is illegible and have faded away. ADAM? What's the meaning this? This isn't looking good. The Marine opened the sealed heavy door with ease and then heard afamiliar computer voice,coming from somekind of mini-drone:

"It's about time Marine. Do you remember me, VEGA?"

He nodded.

"Good Marine. I've been waiting for you to wake up from your slumber. Quick, follow me to the control room of the base."

Following the drone, while walking in the corridors of the base, he noticed that was almost like the Argent Energy Plant, after the Hell Wave. A lot of bullet holes and water leakages everywhere, coupled together with various animals and some skeletons. Some unpleasant memories came back...

After a long walk (damn this base is really big), they arrive at the control room and then VEGA starts briefing Doomguy about what's happening, after uploading itself on the main computer of the base:

"Marine, apparently you arrived in this alternate Earth in the year of 2031. I don't know how you got here, but it's apparent that Dr. Hayden double crossed you in the end. Continuing, you landed in the Mojave Desert, unconscious and you were recovered by the US Military and brought here to this facility and somehow they, stripped you of your armor and guns (somehow), and put you some type of stasis chamber and started experimenting with you. They retrieved many blood and DNA samples from your body, in hopes of finding something useful to them."

"One year later, however, an Alien race started invading Earth and all humanity banded together to defeat them. But they were losing and being exterminated in a fast pace, so they turned their hopes to you. They've tried many times to wake you up, with no success. Then they've started a program called "ADAM" (your codename), and gathered volunteers. The rest of the data is corrupted, but what I've gathered that you're related to some subject called 'Black Rock Shooter'."

"Also, in their desperation, they've damaged the Tether System and we need to fix it, if we want to go back to our timeline. From the information I've managed to recover, the UAC/Alien technology are very similar (especially since they make use of gateway technology), so if we find their main base (and their main portal), we'll be able to reverse-engineer their tech and repair the Tether Prototype. Grab your guns in the Armory, upload me into your armor and let's get out of here."

After rebooting VEGA into the Praetor Suit and getting back his arsenal (untouched and with all mods, even the BFG-9000), VEGA guided him to the exit. After destroying the massive steel door (and some aliens that were trying to invade the base) with a barrage of rockets, he looked towards the wasteland. The once great city of San Francisco now was just a pile rubble and filled with murderous aliens. The Marine swapped the Rocket Launcher for the Chaingun, focusing on finding that alien base and that so called "Black Rock Shooter", he thought to himself:

"Time for the final judgement".

- To Be Continued...