A/N: Hello reader. This is the official rewrite of my L4D fanfic "L4D: Origins". The first version was posted on the forums at , and in general, it was well acclaimed - though towards the end, I was dissatisfied with my first draft, and thus, I began to rewrite my story from the ground up. I personally believe that I have done a much better job on this rewrite than I did on my first attempt. As such, I consider this rewrite (on ) to be the official canon of the L4D world depicted in my fanfic. If you decide to read the first version, it is not the same. If not, then here is the canon version of "L4D: Origins" for your enjoyment or hate or whatnot. Please read and review, offer constructive advice, make me sandwiches, whatever.

I'm sure Valve understands that I don't claim to own any parts of the L4D intellectual properties. But, just in case, I'll put it in now: I do not own the rights to any of the characters, infected or other Valve created intellectual properties. When I say "canon" I mean it in the context of this fan fiction - that is, my (the author's) interpretation of how "L4D: Origins" goes. That means the first version I wrote is not official canon. But, I own whatever rights there are to both versions. Any original characters or settings are my own creation and are thus my intellectual property. Also, I have taken my own creative liberties in writing the story. Although most of the major parts remain the same as portrayed in the game, a few things have been changed to either make things more realistic or interesting. You may read, please don't take without my permission. So no including my OC's in your fanfic without my approval. And don't be afraid to ask, I probably don't mind anyway.

Enjoy.

-Lardcake212

01: Disturbing Behavior

It's one thing to fight a human enemy. Humans can think and rationalize. They have the ability to adapt – moreover, humans fight for a cause, something that they believe is right. Throughout history, men motivated by a cause have fought other men motivated by a different or opposite cause. It is fighting for a cause that differentiates them from animals.

Animals don't fight for a cause. They have not yet ascended into that level of deep thinking. True, some animals like dolphins and chimpanzees have been observed displaying remarkably complex behavior. Yet on the whole, animals fight for survival. In the cruel world of nature, resources are scarce. Conflict rages daily – fought by tooth and claw. There is only enough food, water, and habitable space, to support a limited number of individuals in a species. The math is simple and brutal: some will live, many will die. This brutality ensures that the fittest survive and reproduce.

Something in our past triggered the ability to harness and control the power of the environment. Suddenly, fire was not a deadly enemy, but a useful tool that allowed man to survive harsher conditions than ever before. The eating of meat saw an increase of brain matter from the sheer amount of protein intake, allowing ever more complex hunting strategies to be developed. Today, we have grown so accustomed to taming the environment to our needs that we no longer have to fight for resources. Instead, we fight for religion, political ideals and values.

Then, on a cold November morning, something changed. The first case of "super rabies" was recorded in China. A young boy had returned from a fishing trip with his father. Nothing seemed to be wrong, according to reports, until he developed a high fever and started exhibiting some rather disturbing behavior. The boy stopped speaking after a while and began spewing out nonsensical gibberish. He had to be tied down to his bed because he was so aggressive. Doctors from all over China inspected him, and found the cause – it was a virus. However, it was definitely not rabies. The doctors had discovered something new. No one could say how the boy had gotten the disease. It was not an animal bite, because no marks were found on his body. Perhaps it was a waterborne illness, but the doctors tested the water of the river where the boy and his father had gone fishing; they found nothing. Some even suspected a biological weapon.

No one ever found any answers because within a few days, the infection spread around China and the rest of Asia like wildfire. The People's Liberation Army had to be mobilized and soon, broadcasts and communications from China were cut off entirely. We don't know if the virus had overrun the country, or if the government was just covering up what was going on there.

Just in case, America blockaded her shores, but it was already too late. Cases popped up within our own borders. The first of the infections started on the West Coast – probably by illegal Asian immigrants sneaking in to avoid the devastation in China. The US-Mexico border was well fortified, but people still were able to find ways in. Infections sprang up in the southwestern United States and simultaneously, more cases were recorded in Florida. The sheer speed at which the virus propagates is astounding. Only two days after first infection, a state of emergency for the entire country was declared.

The virus known as "super rabies", as said before, has no resemblance to rabies. In fact, it is more like the common cold in its virulence. It is fully airborne, waterborne and of course, spreads easily through bites and scratches. The incubation period of super rabies is difficult to say – but it has to be quick. The time between the first symptoms (regular flu symptoms) and transformation to rabid killer is inconsistent. For some, it was days. For others, it was only hours. And occasionally, some people would simply transform spontaneously.

The infected people that have turned are, to say the least, extremely vicious. At best, they will struggle against their restraints, even as they rub the skin off their wrists. At worst, they'll be sprinting around and attacking everything in sight. It is easy to tell the difference between an uninfected human and an infected one. Generally speaking, the infected human's skin has turned gray and their eyes have turned red. They are also typically attacking something, which often turns out to be an uninfected human. The sheer brutality by these creatures is unmatched. Individually, they are dangerous and should be avoided at all costs. In a group, they will literally tear a struggling victim limb from limb.

They are completely merciless and endlessly brutal. This virus has more or less produced zombies, at least in the modern sense of fast, viral zombie. They are not invincible, of course, but still take more punishment than a regular human being. The only thing we do know is that they display no sense of self preservation. In the end, they'll have to die.

Until that day comes, we are at their mercy.