A/N: This is my first proper attempt at a multi-chapter fan-fiction, although I have written shorter pieces before. Feedback and constructive criticism would be greatly appreciated, both the good and the bad. So, without further ado, here it is:

A large CEDA Laboratory. One week after first infection.

A nervous young laboratory technician stood before the shift's supervisor. The lad had short brown hair, green eyes and a thin mouth that always seemed slightly downturned, as if he was constantly annoyed at something.

"Mr. Collins, we have a problem,"

"What is it now, Jenkins? I hope you haven't spilt another sample. This is-"

"No! We were testing the effects of our vaccine on an Infected last night. Upon checking on him today… it was horrid. He was hugely bloated, and when he saw us, vomited all over Tom, Matt and Brooke. We've got them in the sick room, but they're showing the symptoms… I think they're about to turn!" The young man was panicking, and his superior put a hand on his shoulder to calm him down. "Listen, son, accidents happen. This virus is like nothing we've ever seen before. Why, I-"

"You don't understand, sir. We performed genetic tests yesterday, and told the non-immune to stay home. Everyone here today should not be able to get infected,"

Maxwell Collins, a stern but kindly man in his early forties, his hairline already receding, dropped the pen he was writing with.

"Initiate a quarantine of this facility. Nobody leaves or enters. If this new strain of the Green Virus has mutated to infect previously immune hosts, we have to keep it contained,"

"Understood, sir,"

"And stop calling me sir, boy. My name is Maxwell,"

"Yes, s- Maxwell. I'll go inform the others,"

The previous night, a common infected had been used in a trial of a vaccine. This iteration was a quickly prepared one, merely to see its effects and whether it could have potential. However, the Green "Flu" had reacted severely, mutating into an even more unstable version. The host had appeared to calm for a while, but overnight the subject's bile production, amongst other things, ramped into overdrive. This became what would later be known as a Boomer.

So when the researchers, foolishly ignoring safety precautions, had opened the door of the room containing the bound Infected wearing only face masks to filter the pathogen, it vomited it's bile onto them. It was unable to move, but they had not expected it to vomit onto them.

This new form of the disease was capable of bypassing their natural immunity, and so they began to turn.

These researchers had been locked up in holding rooms to monitor their condition, while the rest of the staff were not allowed to leave, but had free roam of the facility.

Thomas Simmons, a soft-spoken and friendly man who smoked a pack a day, grew large cancerous lumps on his face and neck. His tongue elongated and became whiplike, and he began to produce a thick black smoke.

Brooke Harris mutated quite similarly to the Infected that attacked them. Her body began to produce large amounts of acidic, glowing goo, to the point where it overflowed out of her mouth in a steady dribble.

Matthew Deluna was the least visibly mutated. His senses grew keener; his fingertips grew sharp claws, his limbs and muscles mutated to become resistant to impacts and capable of pushing off the ground at a somewhat higher speed. The shape of his spine was changed, standing upright would be uncomfortable.

Over the course of the next two days, they were monitored. The mutated virus in their systems stabilized, no longer able to infect the immunes, but (theoretically, nobody was stupid enough to test it) still able to cause mutations in non-immune.

The three immune mutants had been physically changed, but their state of mind remained stable.

Unfortunately for the normals, the other mutants were not happy with captivity.

On day 3, the Spitter, Brooke, used her acid to melt through her bonds, and repeatedly spat at the door until it weakened sufficiently for her to break it down. She then freed me and the others.

I was reluctant to leave at first, knowing the facility was still under lockdown.

But it soon became clear to us that something had gone wrong. The walls were painted with blood, and corpses were scattered throughout the halls. Infected wandered around, screeching and occasionally bumping into a wall or tripping over a chair. But they looked at us intently, even made way for us as we walked.

To my horror, I realized that the Green "Flu" had become a pandemic.

And I was one of them.

For a year, the survivors gathered in small communities, barricaded themselves from the infected, grew their own food, and survived.

After wandering for a while, exploring, I found myself in a large town with the optimistic name of 'River City'. The Infected had overrun it quickly, so supplies of food for me to scavenge were plentiful. Leaping about the urban centre is still exhilarating to this day. Hunters, they call my kind. An apt name, I suppose.

But I've noticed normals have been congregating near River City, digging a trench of some sort. One or two groups of scavengers heading into the city, riling up the commons with their guns.

I don't know what they are up to, but I'll never be able to convince them I'm sane. To the normals, I'm just another rabid monster out to kill them.

Am I?