The planet Androzani Minor, the distant future. In the planets' caves war rages between government troops and the android warriors of the mysterious Sharaz Jek. But what makes spectrox, the substance they battle to control, so valuable? And how far will the Doctor go to protect his companion?
Elenco: William Hartnell , Patrick Troughton , Jon Pertwee , Tom Baker , Peter Davison , Colin Baker , Sylvester McCoy .