The Doctor has to defeat not only the Mandragora energy, but the evil schemes of the murderous Count Frederico who plans to usurp the place of his nephew, the rightful ruler of the province.
 

Forced by the Mandragora Helix to land in fifteenth-century Italy, the Doctor and Sarah find themselves at the mercy of Heironymouse, court astrologer of the province of San Marino. But Heironymouse and other members of his star-worshipping black magic cult have also been taken over by the Mandragora energy form - they will be used as a bridgehead that will enable the Mandragora Helix to conquer the Earth and rule it through their chosen servants.

Doctor Who - The Masque of Mandragora was first broadcast in 1976 and was written by Louis Marks. This adaptation is by Philip Hinchcliffe, who was producer of the programme for three seasons.
 

It is the Italian Renaissance during the corrupt reign of the powerful Medicis. Doctor Who, angry because he was forced to land on Earth by the incredible Mandragora Helix, walks right into a Machiavellian plot. The unscrupulous Count Frederico plans to usurp the rightful rule of his naive nephew. This, with the help of Hieronymous, influential court astrologer and secret cult member. Intent on righting all wrongs, Doctor Who studies their political maneuvers. He uncovers a larger, even more malevolent plot - a plot to rule not only San Martino Province, but the entire world! Hieronymous has been taken over - both in mind and body - by the Mandragora energy ball, an alien, but all-powerful intelligence. Using Hieronymous and his cult members as a bridgehead, the Mandragora Helix intends to conquer Earth and dominate its people!

The question is, will Doctor Who prove a true Renaissance man? Will he be able to drain the Mandragora of its power and foil the Count as well?