In 19th century England, the Sixth Doctor (Colin Baker) finds himself facing two competing enemies: his old adversary the Master (Anthony Ainley), and the Rani (Kate O'Mara), another Time Lord with a sinister plan. The local population and turning violent and unpredictable and, with a major meeting of the brains of the Industrial Revolution due to happen in the village soon, the Doctor must work out what exactly is causing all the problems...