You are a USMC marine specialising in recon and tactical strikes.
The Strogg first landed on earth some 3 years earlier, the first indication being their many crafts pummelling through the earth's atmosphere and hitting home like flaming meteorites. They emerged from their still sizzling space craft and efficiently began to maim and kill and capture all human organic material they could find. It became clear all too quickly what their intentions were. They weren't here for minerals or precious planetary resources - they had come for human meat. The humans they captured could be sure of one thing only, they were going to be sliced to pieces still screaming, still crying, and their body parts and organs would be stockpiled in preparation for the manufacture of new cyborgs. This cruel harvest meant the annihilation of all life on earth, but the Strogg showed no emotion in their actions.
Earth's military forces forgot their differences and joined together as the people of earth to fight the Strogg. The EDF, or Earth Defence Force, was initiated, and began sending the soldiers to battle. The soldiers went willing to die for their race, and die they did. After the 2nd year the casualties had surpassed both world wars put together, hundreds of millions of bodies carpetted the red fields and planes, most missing organs or limbs. They were the lucky ones. Others were rounded up and taken aboard special VTOL alien vessels, the surgeon vessels. Once aboard they were put into laser cages to await dissection. Aboard each vessel resided one surgeon, a mostly mechanical abomination of knives and blades. It would work continuously whirring into the night with its nightmarish arms of death to proliferate the screams that chilled the awaiting captives' minds to the point of madness and suicide. Earth intel at the time discovered that each of these vessels worked to its full capacity and then returned into low geosynchronous orbit above the earth to dock at the mothership, named by the humans the Space Station Behemoth. There the parts would be assembled into new cyborgs and these sent down to fight on earth, completing the hideous chain.
Earth intelligence's study of the aliens was very successful and discovered many things. During the initial bombardment of alien barracks and surgeon craft, one other craft was detected and deemed to be a colonisation vessel. This colonisation vessel's aim was to pass undetected to a point on the planet's surface and then for the aliens on board to transform the ship into a permanent Strogg city on and beneath the planet's surface. EMP or electro magnetic pulse imaging was able to get a VERY rough idea of the city's location and come up with useful data. The city is vast, with a considerable amount underground. Complex tunnel systems were employed to allow for surprise attacks and the seeming disappearance of alien patrols into thin air, when they had actually gone back underground to return to base. However there did not seem to be an entrance above ground, though there must be at least one: the main drop pad. This is where ships come to unload and load and must feature an entrance somewhere. It became a matter of trying to find a tunnel entrance in order to get inside the base. One particular USMC squad managed to do this by following a Strogg patrol back silently and slipping in behind them. They never got out alive but they did get a radio message back to base. Its general message told that it would be too hard to get to the base through the tunnels as the monster concentration and security measures were too tough. However in the tunnels at a certain point is a plan of the city. It holds the co-ordinates of the main drop pad and what is essentially the front door to the alien city. They were cut to meat before they could relay the points.
A few hours ago:
The wars against the Stroggos invasion force rage hotter and more violent than ever. The people of earth continue to wage their war to protect their homelands and families from the onslaught of the legions of Stroggos.
The barracks Alpha though Gamma were all concerned with the finding of a tunnel entrance and it was their collective task to bring back these co-ordinates in order that a marine drop could be carried out. Your HQ maintains continuous contact with these barracks in question, due to their probable proximity to the alien forces. Yesterday at 0500 hours the hourly transmissions from Delta Barracks stopped, and failed to start again. Delta Barracks are believed to have been hit by a roving Strogg patrol. Today half an hour ago Gamma barracks managed to report a similar attack on them before being wiped out. It is believed that they were hit with the same patrol - this would mean that it is highly likely the patrol will pass Delta Barracks on the way back to the tunnel entrance... however, there are complications. Delta Barracks was, as well as a tunnel finding outpost, a stockpile for some of the tactical nuclear weapons the EDF issued for use against the Strogg city. These are comparatively small but high tech nuclear weapons, 150 kilotons or less. However they are all stored together in an underground bunker accessed through a floor hatch in the barracks, and their proximity means that any one exploding will most likely lead to some serious destruction. There are two possibilities that the EDF do not want: either they are leaking radioactive fuel, or the Strogg have acquired them. However it is just possible that they are intact. Your mission is to be airlifted into the regions of the barracks, and to make your way there being sure to monitor any possible radiation. When you get there assess casualties and damage and make your way down to the nuclear stockpile and assess its status. This done, reconfigure the communications desk and relay this information back to HQ. Then await further orders or an airlift home...
Your feet slam to the ground. You watch as the viper pilot readies to VTOL the hell out of there... you wonder if you'll be going home in one of those soon. You grip your standard issue machine gun tight - at least now that you'd been promoted you could head into battle with reasonable firepower.
You glance around you, a sheer wall, a narrow path behind you. Which way to the barracks? What will you find there? Will it be time to meet the Strogg once more? You remember your first year of fighting like a bad dream. The viper shoots off into the distance and your muscles tense. Time to move...