Origin of the Zombie Horde

For years now, there have been rumors at the park. Paintball players occasionally thought they saw something "else" hiding in the woods. Unfortunately, no one ever believed them when they spoke up. Occasionally these same players would wander off into the woods alone in search of whatever it was they saw. While most returned unharmed, some paintball players never came back. At the end of the day when moms and dads came to pick up their sons or daughters, we had no choice but to sacrifice the parents telling them to “go look in woods”. When the parents failed to escape alive we sold their cars to the scrap yard so no one would get suspicious. For years, we have tried to keep our little problem a secret. As the number of sightings went up, so did the number of paintball players who wandered off into the woods alone. We were starting to have a serious problem on our hands.

Recently we assembled an elite group of handpicked mercenaries to investigate our now serious problem. The team returned from their reconnaissance mission and had this to say.

Ok, so what’s the deal? They reported "THERE ARE ZOMBIES IN THE WOODS!"
When we asked how many? They replied “TOO MANY TO COUNT!”
Why didn’t you shoot the zombies? They shouted “OUR BULLETS HAD NO EFFECT!”
Ok, so what’s next? Their final remark “YOU ARE ON YOUR OWN, WE ARE OUT OF HERE!”
I could not believe it, my very own handpicked team of mercenaries quit on me. I have no choice but to make this public announcement and formally ask for your help.

On orders from the CDC (Centers for Disease Control), we have built walls and have established a quarantine zone around the zombies. Only individuals with the proper security clearances may enter the containment area to help eradicate the zombie horde. The CDC has formulated an experimental neurotoxin designed to infect the infected. This liquid neurotoxin now fills our glowing 68-caliber tracer rounds. Sit down at one of our mounted machine-guns and fire away at the zombies infecting as many as you can.