Burnt-out home carer Kate finds herself in uncharted territory when her favourite cranky client Doug drops some unexpected news.
The Doctor and Peri arrive in London responding to an emergency alert from the Brigadier. They discover that the prime minister has been replaced by an auton duplicate. The autons continue their plan to Singapore with the help of the Master.
Con men, deposed Presidents, and sleeper agents, The Doctor returns to his home planet to find it in the process of imminent destruction!
