Radiation nil, oxygen normal, pressure normal, yet London is deserted, with no sign of life and no sense of normality. Exploring the decaying city sometime after 2164AD, the Doctor and his companions soon learn that it is not as empty as it seems. The Daleks - far from having been destroyed on Skaro - have conquered the world. Nearly wiped out by storm and plague, the Earth's population has been commandeered by the Daleks into huge mining operations. Some humans have suffered the further indignity of being transformed into Robomen to serve the Daleks in their diabolical plans. Humanity's only hope for survival lies with a small band of resistance fighters.