Here we go!
(Quoted from my post on the Yoyogames Forums)You were once just a normal person living in a large city. You would go around and do normal things like normal people, and you got sick like a normal person. You had the sniffles and stayed home one day from work. As you were [insert moderately dangerous household task here] you cut yourself badly (can be changed to something more easily noticeable, as the graphics are a bit small to see a cut on the player). You watch as your bloody gash closes up, turns into a scar, then recedes away into fresh skin. Immediately, you jump in your car and fly off to the hospital.
At the hospital, you meet a doctor and tell him what happened. He doesn't believe you, so you cut yourself on one of his instruments and both of you watch it heal back up. The doctor gets up and grabs the phone to tell the dean of medicine about what had happened. You get sent home, considering the fact that there isn't really anything wrong with you. Days later, government officials arrive at the door asking if you'd like to "help them out." You decline, and close the door, but then you are carried off by a Swat team due to "national security" reasons minutes later.
You are taken to a testing facility, where you are tested on by many scientists where they find that you have a mild case of a disease that decays flesh when fully infected. For you, it enables you to heal miraculously. As you are imprisoned in the testing facility, you meet a scientist who has some sympathy for you. For this reason, she helps you escape from the facility and you run away into the wild to live as a hermit.
While you are out living as a hermit, the disease is bought by a private company (what type would it be?) that says they are going to create a cure for the disease. They work on this cure for a long time until they believe they have perfected it. As long as the person being treated isn't completely infected, the cure will be able to return them to normal. After the company finishes developing this cure, they see that the disease has not infected anyone, and so they set it loose in the hopes of making great profits with their cure that only they have. All of the people who are sick will come to them to be cured, and they will make a lot of money in the process. Sadly, the company waits too long after putting out the disease to begin releasing a cure, and the disease had mutated to the point where their cure was useless. The people at the company quickly ran away, along with many of the people who had tested on you, because they knew what would happen after the infection took over.
You, of course, are sitting off in a shack in the woods completely oblivious, until you find a radio and receive an ominous message. The city had been completely overrun and very few were still alive. You had grown tired of your time as an infected mutant and wished to return yourself and all the others to normal, but you needed to find a new cure that could fix the disease as it is now. You head off into the city in search of the woman who had set you loose from the testing facility.
On the way, you meet 3 people who help you get to the woman. First, you play ten levels until you find a man who has just been infected a day before. The disease hasn't caught hold of his nervous system and brain quite yet, but it is obviously close. You cautiously approach, ready to kill him, when he speaks out. He tells you about what the virus is, what it's called, and what it does. After he is about to finish, he transforms fully into a member of the infected, and you must kill him before he kills you. You continue on until you get to the city and go to the facility you were tested at where you find a second person who tells you something important (where the woman is? But when you get there she isn't there and that's where the third person comes in?). You find the third person who tells you exactly where to find the woman, you get there, and have to protect her while she creates a cure. Then you become cured and give the cure to a higher authority who finally do the right thing and start sending out soldiers to inject the infected with the drug until they are cured.