'MY COMMAND PROGRAMME HAS BEEN RESTRUCTURED,' EXPLAINED THE ROBOT PLACIDLY. 'ALL HUMANS ARE TO DIE.'
On a desert planet the giant sandminer crawls through the howling sandstorms, harvesting the valuable minerals in the sand. Inside, the humans relax in luxury, while most of the work is done by the robots who serve them. Then the Doctor and Leela arrive - and the mysterious deaths begin. First suspects, then hunted fugitives, Leela and the Doctor must find the hidden killer - or join the other victims of the robots of death.