The Setting (as seen in the opening of the Pilot episode)
Two years from now, The Higher Hopes Foundation - a medical research facility in Shreveport, Louisiana - will create the prototype for a vaccine that is designed to rid the world of the HIV virus. Upon testing, it is discovered that the vaccine may also contain some regenerative properties that, if successfully enhanced, will allow the human body to essentially heal its own damage to a limited extent.
Four years from now, with the vaccine still in its experimental phases, The Rising Corporation in Denver, Colorado (rival to The Higher Hopes Foundation), will hire a team of the world's most successful practitioners in the craft of theft to steal the vaccine and all the research that goes with it. The operation is a success and Rising immediately begins extensive experimentation, much of which falls outside the bounds of legal practice. Lab technicians test various new forms of the vaccine on rats, horses, pigs, birds, fish, monkeys, human volunteers, and even on the corpses of John and Jane Doe's who lay unclaimed in the local morgues.
Five years from now, the results of Rising's carelessness bring about a swarm of human bodies, neither alive nor dead, wandering the streets and feasting on any living being they can touch. Once bitten by these living corpses, the victim falls prey to the vaccine-turned-virus, joining into the ranks of the Diseased mere hours after infected saliva mixes with living, flowing blood. All attempts to stop the rapidly growing numbers of the putrid masses are in vain, felling entire armies, then entire nations. The living are left to roam the Earth in small numbers, constantly on the run from both the Undead and from each other. Laws no longer exist, crime runs rampant, there is no trust amongst those who survive together in wandering communities, and fear becomes the one and only constant.
But, there are those rare survivors who still hold out hope for humanity. They haven't given up on the world just yet, and will risk everything to fight for the lives they used to have. Somewhere out there, there exists a cure for the virus man created, and it becomes the sole mission for the brave few left with their souls still intact to find it. These men and women, these heroes, are the last spark of salvation for mankind, and they will stop at nothing save death itself, to put the planet back in order.
This is their story...