The story of Half-Life? Check this out. I wrote this a few nights ago. See if it fits.
Half-Life's story begins long before the Black Mesa incident was even a thought in anyone's mind. The border world of Xen was begining to use up the last of its resources, spelling the end of the planet and the aliens that lived there. It was decided by the rulers of the planet to seek out another planet with decent resources that they could use for their benefit.
They settled on Earth, a planet quite some distance away.
Since Earth was so far away from Xen, it would have been impossible to launch an assault directly from the planet itself. They needed a way to put their teleportation technology to use, but without a gateway into the planet there wasn't any feasable way they could use their technology. After some deliberation, the rulers decided to try and get the Earth people to open the gate for them using their own technology.
The G-Man, our friend with a speech impediment, was sent on the long journey to Earth to set that plan in motion. His craft crashed in Roswell, New Mexico in 1949 and he successfully escaped the wreckage. The American government stated the craft was a weather balloon. The G-Man assumed the identity of a government agent and proceeded to the American capital as a lobbyist for research.
He worked for years, managing to get the government to agree to limited funding to such a project. They commissioned the construction of a top secret reserach facility in New Mexico, name Black Mesa. The facility was complete in 1967 and research started.
The G-Man hung around as the base and the experiments grew larger. The scientists were making huge progress, studying samples of Xen minerals the G-Man had brought with him. In 1987, the Black Mesa Facility opened the first warp gate to Xen. They began sending science teams to the planet, which gathered fauna, animal life, and minerals for study. The Lamda complex was responsible for most of the research. The G-Man was pleased with this.
Research continued for many more years, and science teams began disappearing. Research ceased with Xen and the study with the teleportation technology increased. In 1996, the G-Man planted the purest sample of a Xen mineral known as Etheral, which wwas designed to react vioently with the Earth machines. When the mineral was hit with the analysers, it would open the gate and Xen forces would flood the planet. Now, they needed someone to do it for them.
Then came Gordon Freeman.
Dr. Freeman was a 24 year old genius with a doctorate in Theoretical Physics from MIT who had just been employed at the facility two weeks prior by his former professor at MIT, Dr. Issac Kliner. Dr. Freeman had a position in the Anamolus material lab, and they were the ones who would be analysing "the purest sample of Etheral they had seen yet."
When Dr. Freeman began analysing the mineral, all hell broke loose.
Dr. Freeman's hazard suit allowed him to survive the explosion in the test chamber, and he managed to escape and began trying to get out of the lab. Dr. Eli Vance instructed him to get to the surface and tell someone the science team was in danger. Dr. Freeman complied and began heading to the surface. Finding a crowbar, Dr. Freeman began the long trek to the surface.
He fought his way through the Xen aliens and zombified science team members with thee help of armed security guards as far as he could possibly go before it became evident that getting to the surface would not be an option. The Xen aliens had begun sweeping across the American homeland, and the government pinpointed Black Mesa as their arrival point and sent a cleanup team of US Marines to sweep the facility. Dr. Freeman fought through increasingly difficult battles with soldiers ans aliens unitl he reached the Lamda complex. There, the science team agreed to send him to Xen to stop the invasion from its source. They did so, and Dr. Freeman faught his way all the way to the ruler of Xen, Nanalinth. After defeating Nanalinth, Dr. Freeman blacked out and was recovered by the G-Man, who had been watching him since the begining.
Dr. Freeman could not stop the invasion, and the G-Man realized that his services could be valuble to the Xen cause. Dr. Freeman was blackmailed into assisting the G-Man and his bosses. When he awoke, he was aboard a train heading to City 17. After wandering around, he met up with Barney Calhoun, a secuirty guard at Black Mesa, who told him to meet Dr. Kleiner at his lab. Groups of soldiers known as the Combine littered the streets, and they didn't take kindly to Dr. Freeman wandering without being told. After a breif chase, Dr. Freeman met up with Alyx Vance, daughter of Eli Vance from Black Mesa. She took him to Dr. Kleiner, who attempted to send Dr. Freeman to Eli's lab. When the teleport failed, Dr. Freeman wormed his way to the lab on foot.
THe newspaper clipings Dr. Vnace held onto showed that Earth had surrendered to the Xen soldiers and the surviving humans were sent to concentration camps known as "Citys," like City 17.
That's all I've got so far...
