Great Britain, 2007. A deadly plague, known as the "Reaper Virus," has broken out, killing hundreds of thousands in its wake. In desperation, the British Government evacuates as many survivors as it can out of the infected area, and then builds a wall, preventing the remainder from escaping. Thirty years later, with the wall still up and the victims all but forgotten, the virus breaks out again. The Government decides to send a crack team of operatives, led by Major Eden Sinclair, into the hot zone to investigate the possibility of a cure.