Three mysterious sisters have been terrorizing a convent/ boarding school, kidnapping the students that see them. The Doctor and Leela arrive to investigate, and team up with Dame Emily Shaw, the mother of former companion Liz Shaw, to find out where the students are.
The Cloisters of Terror contains examples of:
- The Bus Came Back: Roweena Cooper reprises her role of Dame Emily Shaw, now alongside the Fourth Doctor.
- Call-Back: The Third Doctor saving Emily from being killed was mentioned.
- Call-Forward: A spaceship is hidden underneath the school.
- Haunted House: The students believe St Matilda's is one, with reports of ghostly nuns running around kidnapping them.
- The Nth Doctor: Discussed by Emily and the Doctor. Emily nearly gets the concept but concludes that the Fourth and Third Doctors just share the same name (their alias "Dr. John Smith") and the Fourth is his replacement.
- Parrot Expo-WHAT?: When the ghost-skeptic Doctor first hear of the ghostly nuns.Emily: ... Even though her roommate thinks she has been abducted by ghostly nuns.Doctor: Abducted by the ghostly- what?
- The Smurfette Principle: Inverted; Tom Baker's Fourth Doctor is the only male character in the story. Justified since the story takes place in a women's convent.