It is set in England in the late 15th century and centres on the fictitious Prince Edmund, who finds himself falsely accused of witchcraft by a travelling witch-hunter known as the Witchsmeller Pursuivant.

Academy Award-nominated actor Frank Finlay guest stars in this episode as the Witchsmeller, and Valentine Dyall appears in a cameo.

Prince Edmund, accompanied by Percy and Baldrick, goes to find out more about the Witchsmeller from the local village, but discovers the remains of a woman who has already been burned at the stake for witchcraft, along with her cat.

Prince Edmund stands trial; Percy and Baldrick are appointed defence lawyers, but the Witchsmeller silences them before they can even start their case by condemning them also as witches.

The Witchsmeller interrogates Edmund and presents three pieces of evidence in his case: Prince Edmund, who he dubs "The Great Grumbledook", has a pet cat named Bubbles (which the Witchsmeller says is "short for Beelzebubbles") who supposedly drinks blood; he has allegedly engaged in acts of bestiality with his horse, Black Satin, who supposedly has the ability to talk (the horse later dies during interrogation, but leaves a signed "confession"); and he is accused of having sexual relations with an elderly peasant woman who claims to have then given birth to a poodle.

Breaking the fourth wall, the Queen looks at the viewer and winks as magical sparkles fly from her eyes and twitches her nose in a pastiche of Bewitched.

A production assistant on the series, Hilary Bevan-Jones, recalls that she forgot to pick up Finlay from the location at the end of a shoot and left him behind, until the make-up team found him wandering in the snow in full Witchsmeller costume and brought him back to the hotel.

Robinson recalls that during the filming of episode 5, he realised that re-using the word "cunning" could be an effective comedic device and he inserted it into his line "I have a plan" as Baldrick conspires with Edmund to escape from the dungeon.