Plague: Secrets and fears

It's been five years since the infection began. Since people started getting sick and dying, and then coming back. Five years since the world ended. This infection was created by Damon Frost. He was a genetics and anatomy scientist who was paid by the government, yes the government, to make a bacterial weapon. The weapon backfired however, and was released on the public, causing the sickness, the death, and the panic. Now five years later the infected roam free, the few remnants of humanity group together in safety military zones across the country, but the survivors who don't stay in the zones are scattered. Living in small groups, no one can survive alone for very long. I have though. I've been alone since the beginning. Don't ask why, don't ask how. I won't tell you. I won't say much of anything, I don't trust anyone these days. No one can even know my name, let alone that I'm a girl, without trying to kill me, and me being forced to kill them. Who am I? Well, didn't I just say you'd try to kill me if you knew?