OVERALL EPISODE NUMBER: 561
STORY NUMBER: 118
TRANSMITTED: Tuesday 05 January 1982
WRITER: Christopher H. Bidmead
DIRECTOR: Fiona Cumming
SCRIPT EDITOR: Eric Saward
PRODUCER: John Nathan-Turner
RATINGS: 8.7 million viewers
FORMAT: DVD: Doctor Who - New Beginnings (The Keeper of Traken/Logopolis/Castrovalva)
The Doctor makes his way to the console room with the aid of an electric wheelchair and programs the Tardis' architectural configuration to delete 25% of the mass to provide the boost for them to escape event one. However in the process the Zero Room is deleted leaving Nyssa to make a Zero Cabinet out of the remaining door panels. Tegan lands the Tardis, awkwardly, on the planet Castrovalva, famed for it's tranquillity. Tegan & Nyssa try to transport the Zero Cabinet using the electric wheelchair, but the wheelchair is damaged in a stream so they hide the cabinet and try to find the dwellings of Castrovalva on foot. When they return the cabinet is empty and blood is on the ground nearby....
A little bit of a nothing episode... essentially it serves as a bridge between the threats of episode one and the main thrust of the story in episodes three & four.
Two more locations pop up in this episode: Buckhurst Park, which provides the woodland setting and Harrison's Rocks, which is the climb to the dwellings of Castrovalva. Harrison's Rocks was previously used in a similar way in the Second Doctor story the Mind Robber.
The first and second episodes of this story were seen on the Monday & Tuesday of the first week in January in 1982 at about 7pm. It's the first time that Doctor Who was shown on a day other than Saturday for it's initial airing (there had been repeats on other days before). These days would be Doctor Who's home for the thirteen weeks of 1982 that it was on: twice weekly episodes mean the season lasts half as long. Over the next few years it would wander from day to day over the schedules occupying Tuesdays & Wednesdays for the next season before moving to Thursday & Friday for season 21 in 1984. It's generally interpreted that the BBC was using Doctor Who to try out twice weekly viewing slots in preparation for launching it's own evening soap opera. That turned out to be East Enders which started in 1985 with Doctor Who being returned to Saturday evenings with disastrous consequences for the show. However at the same time as Doctor Who was airing twice weekly the BBC was already having some success with a twice weekly soap opera/medical drama: Angels. That series will crop up on several of the CVs we'll see of actors new to the show in the next few years.