Some study science for all the right reasons, others intend to play god. Dr. Springfield practiced the latter of those two statements. Once his discoveries went public the powers at be. Stole his formulas and attempted to recreate his masterwork. Though they needed live subjects. It was decided that (insert community) would serve as the testing ground.
In the year 2012 on the day of June 3rd at exactly 1600 hrs. A flight of US owned MiG29 fighters released their payload over (insert community). Immediately news reports began to cover the incident. The United states Government denied any involvement, they treated it like a terrorist attack. After all people around the area spotted Russian Migs dropping the ordinance that contained a even greater evil than man had ever seen.
The cover story worked well. Too well within three days the US began military operations in Russia. The toxin contained in the ordinance had failed on creating a superior human being by alteration of genetic structure. Instead anyone wounded by the initial blastsoon perished of flu like symptoms. After twenty four hours post-mortem. They began to once again show signs of life.
Two weeks after the initial outbreak the entire united states was no longer a nation of prosperity. The entire country had been overrun by the living dead. The infection spread at such a rapid rate the CDC couldn't contain it. within 17 days the President had declared war on his own country. A fear that all hoped had been assuaged at the end of the civil war. Almost every major city on the east coast had been firebombed before the infrastructure collapsed entirely. You are one of but a handful of survivors. How will you save yourself?
Side effects from the toxin: No fever from an infected. The person are normally cold. The brain is shutting down along with the heart. A normal human has a body temperature of 90-98 F. An infected body temperature is around 50 F or under. The heart is sometimes still beating just not as fast or at all. The other organ shut down as they are no longer needed. No liver to clean the blood, no kidneys, no lungs as these infected don't breath air. The most primitive parts of the brain are what are powering the infected. Or in other words an infected individual has half or less of a brain than many adult humans, a mentally challenged child may have more brain power.