(Please PM Me)
The population on Earth has exploded by the year 2250. So much so that the population has been creating mobile space station to house the overflow. Several colonies have been established on the moon and Mars. As technology advances by leaps and bounds. Companies have begun crafting spaceships to take selected crews to other worlds looking for another Earth. One exploration crew finds a world much like Earth before cities were built. It has natural resources a plenty. The one thing they did not count on was meeting the world's inhabitants.
Barely making it back to the camp after being attacked, the crew began to depart. Vowing to come back, and this time with more firepower. What they did not know was they were not alone on the ship. They had a stowaway. Returning to Earth, they begin the debriefing, and relaxing after their harrowing experience. Until one of the crew started to experience unusual flu-like symptoms. The stowaway emerges seeking out the infected crew members and the one who seems somehow resistant. The virus soon spreads changing the population in ways no one thought. The spread of the virus soon attracts alien beings, the same ones from the planet the crew visited. As the human evolution begins to ascend to a new level, another evolved species comes to claim their world.
Soon war breaks out between the aliens, the infected and the normal humans. The wars wages for several years. During the time, Gateway technology is developed. Rounding up the infected and aliens, they are put into cryostasis and put on a spacestation and sent through the Gateway. Soon they are forgotten, Earth continues on soon forgetting about the station. Using Gateway technology they begin to explore further into unknown territories soon meeting a variety of aliens, some friendly, some not so much. Technology begins to advance with helpf from alien allies to where Gateway technology now seems obsolete.
But, what happens when the past comes back to haunt you? The forgotten station is discovered and it begins again.The idea is a rough sketch to be further developed through brainstorming. Thinking using elements of Aliens/Species/Predators/Babylon 5/Star Trek. Most likely will be Extreme. Anything goes.