On the cave-riddled world of Androzani Minor, the Doctor and Peri inadvertently find themselves enmeshed in a war fought between the ruthless General Chellak and the sinister Sharaz Jek and his army of androids. The duplicitous politician Morgus wants Chellak to execute the time travelers as spies, while the disfigured Jek seeks to keep Peri forever hostage within his stronghold. But the Doctor soon realizes an even more gruesome fate awaits them – they have been infected with fatal spectrox toxemia, and there is no cure. Hunted by both factions and with death just hours away, how far must the Doctor go in order to save his friend’s life?