Italy, 1492. Not realising the TARDIS has been infiltrated by the malevolent Mandragora Helix, the Doctor and Sarah arrive in the tiny duchy of San Martino. With the locals preoccupied by the struggle for the Dukedom, will the time travellers be able to resist a force that threatens to drag Earth into a new Dark Age?
Elenco: William Hartnell , Patrick Troughton , Jon Pertwee , Tom Baker , Peter Davison , Colin Baker , Sylvester McCoy .