Two years have passed since a deadly disease has ravaged the U.K and the government have finally created the first successful antiserum for the virus. Unfortunately, the virus mutates and causes the serum to become redundant on some of the population causing the government to divide the country to protect those already immune from the new strain. Partnering with private security firm Haven Global, the government sets up research facilities and manufacturing centers in the quarantine zone to observe the virus and hopefully create a new vaccine in order to combat the evolving threat.