A break in at the hospital morgue, the unexplained disappearance of certain bodies, intrigue among the senior staff, and a chance encounter with a grieving widower, prompt Dr. James Saracen to question irregularities surrounding the death of a woman at Skelmore Hospital. Narrowly avoiding personal disaster, he unearths a conspiracy to conceal the fact that she died of a disease believed to have faded out in England hundreds of years ago. The lazy and politically motivated head consultant carelessly assumes that this is an isolated incident. Saracen is sceptical and is proved right when more and more cases are brought into the Accident and Emergency unit. Faced with the outbreak of a highly contagious epidemic, which seems to defy the rules of containment, the town is placed under martial law. Saracen struggles relentlessly against the clock to trace the elusive source of the pestilence and save the Midlands town from annihilation.