This story sees the debut of new Doctor, Peter Davison, in the wake of the immensely popular Tom Baker.
"Castrovalva" is also a continuation of storylines from "The Keeper of Traken" and "Logopolis" and the third, and final, part of a ‘Master Trilogy’ with Anthony Ainley playing the part of The Doctor’s arch-enemy, The Master. Fans sometimes refer to this trilogy as "The Return of The Master" and this name was initially slated for the DVD set of the trilogy. Eventually, however, the trilogy was released on DVD, in January 2007, as "New Beginnings".
This story was a replacement for a story entitled "Project Zeta-Sigma" (or, earlier, "Project 4G") by John Flanagan and Andrew McCulloch - the team responsible for "Meglos" the previous year.
However, with production less than two months away, serious issues began to arise with "Project Zeta-Sigma" prompting Producer John Nathan-Turner to abandon this planned story. With "Project Zeta-Sigma" being abandoned so late in the production schedule the production order had to be reshuffled so that "Castrovalva" was actually recorded fourth in the season. This meant that "Four to Doomsday", scheduled to be this season’s second story, would now be the first to go before the cameras.
To write "Castrovalva" former Script Editor Christopher H Bidmead, who had returned to freelance writing after leaving Doctor Who at the end of Season Eighteen, was asked to write a story featuring The Master in which the new Doctor would be suffering from regeneration trauma (induced by the escalating entropy field encountered in the previous story "Logopolis" that had also been written by Christopher H Bidmead).
Christopher H Bidmead based this story on a couple of prints in the office of Graeme McDonald, the Head of Drama, whose optically illusory nature had irritated John Nathan-Turner. These had been drawn by the Dutch artist and mathematician Maurits Cornelis (MC) Escher, whose works included Relativity (1953), in which figures are seen to walk up or down all sides of a series of staircases, Belvedere (1958), in which the perspective of a building changes between floors, and Ascending and Descending (1960), in which a staircase endlessly loops back onto itself. Christopher H Bidmead thought that an environment exhibiting these sorts of traits could complement a story which dealt with the mathematical concept of recursion, a concept portrayed in much of MC Escher’s artwork. One of MC Escher’s drawings depicts a town in Italy atop a steep slope, a setting similar to that seen in the 1972 Third Doctor story "The Curse of Peladon", but there is nothing in the print itself to suggest the paradoxes of this story.
The director assigned to this story was Fiona Cumming, a former actress who had enjoyed small roles in programmes including Dr Finlay’s Casebook. After a few years she then decided to work behind the camera. This included working on Doctor Who during the Sixties and Seventies, first as an Assistant Floor Manager on the 1966 First Doctor story "The Massacre of St Bartholomew's Eve", and then as a Production Assistant on the 1966/67 Second Doctor story "The Highlanders", the 1969 Second Doctor story "The Seeds of Death" and the 1972 Third Doctor story "The Mutants". Before directing "Castrovalva" Fiona Cumming had directed programmes such as Z Cars, The Omega Factor and Blake’s 7.
The first episode of this story was broadcast on the 4th January 1982, marking the return of Doctor Who to British television after an absence of more than eight months - the longest in the programme’s history to that point.
This was also the first time Doctor Who was not transmitted on a Saturday, but instead a twice-weekly, Monday and Tuesday schedule (This was later to be switched to other weekdays). This change was due to the show faring very badly in the ratings throughout Season Eighteen, as competition from ITV’s glossy American import Buck Rogers in the 25th Century proved devastating to the programme’s audience. BBC1 Controller Alan Hart concluded that the show’s traditional Saturday teatime slot - which it had occupied since debuting in the 1963 First Doctor story "An Unearthly Child" - was no longer appropriate for the show. Also at the same time, the BBC was engaged in long-term plans to introduce a soap opera which would be broadcast on two nights each week; this would ultimately become EastEnders. Before committing to what was, at that point, a revolutionary plan, the BBC was eager to test this scheduling model on an established programme and Doctor Who was selected for this experiment.
This change in format though, was not well promoted, with the result that many regular viewers missed the second episode. According to production notes on the DVD release, some parts of the UK saw the first part at a different time than the scheduled BBC broadcast, in some cases as early as mid-afternoon.
However, one advantage of the overhaul of Doctor Who’s premiere date was that John Nathan-Turner enjoyed unprecedented flexibility in rearranging his recording schedule. Having come to the conclusion that it would be beneficial for Peter Davison to record several stories before tackling his debut adventure, and to allow Christopher H Bidmead more time to write this replacement story, it was decided that "Castrovalva" would be made fourth, after "Four to Doomsday", "The Visitation" and "Kinda".
This story was the first of only four Doctor Who stories in the original run of the show to feature a pre-credits sequence (the others being the 1983 Twentieth Anniversary special "The Five Doctors", the 1987 Seventh Doctor story "Time and The Rani" and the 1988 Seventh Doctor story "Remembrance of the Daleks"). When the show returned in 2005 (starting with the Ninth Doctor story "The End of the World") pre-title sequences became a regular feature.
This pre-credits sequence was a reprise from the final moments of the preceding story, "Logopolis". This though was a slightly revised version than previously seen in the Fourth Doctor’s final story. It contained a shortened reprise of the regeneration sequence with a slightly rescored incidental music, changing it from its original sombre melody, to give it a more up-beat quality. Tom Baker received no credit for this sequence.
New opening and closing title sequences are used. These are similar to the previous season’s version, designed by Sid Sutton, but this time incorporating Peter Davison’s face in place of Tom Baker’s.
This is the first story in which the lead role is credited as ‘The Doctor’ on the closing credits rather than ‘Doctor Who’ (or ‘Dr. Who’). This was a break with a tradition that dated all the way back to the programme’s very first story.
The credit would remain as "The Doctor" until the show’s cancellation in 1989, at the end of Season Twenty Six. In the 1996 television film "Doctor Who: The Movie", no credit was actually given for the Eighth Doctor (although the Seventh Doctor was called the "Old Doctor", albeit not in the onscreen credits). However, it reverted back to "Doctor Who", for all the stories in Season Twenty Seven (New Series 1), when the show was revived in 2005. The title then became "The Doctor" again in the 2005 Tenth Doctor story "The Christmas Invasion" at the request of new star David Tennant.
The Portreeve is listed in the credits as being played by "Neil Toynay". This is an anagram of "Tony Ainley" and was used to prevent prior knowledge of Anthony Ainley’s portrayal as The Master in this story. This was also a play on The Master’s habit of using either anagrams or synonyms for ‘Master’ as aliases.
This story features a guest appearance by Michael Sheard playing the part of Mergrave. Michael Sheard is more famous for playing the part of teacher Mr Bronson, in the BBC children’s drama Grange Hill, between 1985-1989. His previous Doctor Who appearances include the 1966 First Doctor story "The Ark", as Dr. Summers in the 1971 Third Doctor story "The Mind of Evil", as Laurence Scarman in the 1975 Fourth Doctor story "Pyramids of Mars" and as Supervisor Lowe in the 1977 Fourth Doctor story "The Invisible Enemy". He would also play the part of the headmaster in the 1988 Seventh Doctor story "Remembrance of the Daleks".
This story contains the debut of the Fifth Doctor’s cricketing outfit. The Fifth Doctor’s distinctive trademark also comes about in this story when he sees a stick of celery and declares ‘definitely civilisation’. At the end of this story he pins a stalk of celery to his lapel. This habit continues throughout his era, although he does not explain why until his final story, "The Caves of Androzani".
We also see the Fifth Doctor unravelling the Fourth Doctor’s trademark scarf so as to use the yarn to guide his way from the Zero Room back to the Console Room. He is also seen ripping the waistcoat the Fourth Doctor wore in half. He is then seen taking off a shoe and leaving it as a landmark as he made his way through the TARDIS. These though are not the same shoes worn by the Fourth Doctor, in "Logopolis", who wore knee-length buccaneer-style boots in that story. The Doctor has previously regenerated items of his clothes along with his body. At the conclusion of the 1966 story "The Tenth Planet", likewise he has different shoes when he arrives newly regenerated in the 1970 story "Spearhead From Space", the frills on his coat, when the Third Doctor regenerates into the Fourth Doctor in the 1974 story "Planet of the Spiders", disappear as well and the Fourth Doctor, in the 1974 story "Robot", is wearing different coloured pyjamas.
For this story changes were made to Nyssa’s costume. This was achieved during the second episode where Nyssa’s costume gradually transforms into the standard outfit she would wear for the rest of this season: first, she exchanges her skirt for a pair of corduroy trousers before she and Tegan Jovanka begin carrying the portable Zero Room to Castrovalva; along the way, she abandons her velvet jacket, and finally she loses her ornamental hair-comb when it gets caught by a tree branch. By the time she and Tegan reach the base of the cliff, she is more-or-less outfitted as she would be for the remainder of the season.
In this story Tegan is heard to state that she is from Brisbane.
For the final scene, the script called for Adric to look ‘pallid’ as he was still recovering from the effects of imprisonment by The Master. According to the commentary on the DVD, this was accidentally achieved by Matthew Waterhouse, who had a hangover from the night before from drinking too much.
The TARDIS databanks state that Castrovalva is in Andromeda, a planet in the Phylox series, but as with many elements, including Tegan’s ability to land the TARDIS, these are later revealed to have been part of The Master’s plan.
The Cloister Bell is heard again as the TARDIS heads backwards in time towards the beginning of the universe.
To date no story has taken place earlier in time than this story in 13.7 or 13.2 billion BC. The closest second is the Earth’s formation scene in the 2006 Tenth Doctor story "The Runaway Bride" which is set in 4.6 billion BC.
In "Time-Flight", the final story of this season, Nyssa is heard to say that she wished she had known about the feature, The Doctor uses, to shift the interior of the time machine, as it would be on flat ground, no matter how the TARDIS was when it landed.
While he is disoriented, The Doctor is seen displaying mannerisms of his previous incarnations. At one point The Doctor grasps his lapels, adopting the persona of the First Doctor and addresses Adric as ‘Brigadier’ and ‘Jamie’, and Tegan as ‘Vicki’ and Jo. He is also heard quoting the First Doctor (‘I wonder, boy, what would you do if you were me, hmm?’ and ‘Fit as a fiddle, Vicki’), the Second Doctor (‘Jamie, you go back... when I say run, run’ and a scene with the recorder), the Third Doctor (‘Not far now Brigadier, if the Ice Warriors don’t get there first’ and ‘Not forgetting to reverse the polarity of the neutron flow’), and the Fourth Doctor (‘Now, ordinary spaces...’).
In his delirium The Doctor also mentions some of his previous companions. (‘Romana’s always telling me I need a holiday’, ‘Get K9 to explain it to you’ and ‘Where were we, Jo? ’) and old enemies (‘Oh, the Ogrons and the Daleks. I think it does us good to remind ourselves that the universe isn’t entirely peopled with nasty creatures out for themselves’).
It has been revealed that the decision to have the Fifth Doctor impersonate his past incarnations was made during rehearsal when Peter Davison presented impersonations as part of his preparation for taking on the role; his interpretation was intended to combine elements of the past Doctors.This story also contains references to recent Fourth Doctor stories "Full Circle" (‘Ever been to Alzarius?’), "Warriors' Gate" (‘We left Romana at the gateway’) and "Logopolis". The ion bonder from "The Keeper of Traken" is also mentioned.
This is the first mention and view of the TARDIS Zero Room - ‘An isolated place cut off from the rest of the universe’ which is used by Time Lords after difficult regenerations. It is located in a part of the TARDIS that Nyssa states ‘hasn’t been used for centuries’. Inside The Doctor can levitate (and in the Zero cabinet made from the doors of the room after it is part of the 25% of the TARDIS that was jettisoned to escape ‘Event One’).
In this story ‘Event One’ appears to be a reference to the Big Bang - the creation of the universe. However, it is repeatedly described in this story as ‘the creation of the galaxy’, which is believed to be a quiet, tranquil coalescing of hydrogen predating the first stars rather than a dramatic cosmic event.
The Doctor is heard saying that there is a polygonal Zero Room under the Junior Senate block on Gallifrey.
The Master uses a Hadron web, which is powered by Adric, to power Castrovalva.
Sound effects for the jungle/forest in parts two, three and four were taken from a BBC effects record and were of a jungle in Sri Lanka at dawn in the year 1945; other sound effects included a canary singing, a Tibetan horn, wind effects and an open fireplace.
This story contains a number of errors. Namely: Peter Davison’s Fourth Doctor costume has different shoes than Tom Baker’s. In "Logopolis" Tom Baker was wearing high leather boots when he regenerated whereas Peter Davison was wearing ankle-high shoes thereafter; The TARDIS is in a different field from its last-seen position in "Logopolis"; The security guards seen chasing The Doctor’s companions at the start of episode are different to those seen at the end of "Logopolis" – This was due to Director Fiona Cumming casting different actors for one than Peter Grimwade had previously used; When The Doctor levitates in the Zero Room his coat tails levitate too, and the image used is horizontally flipped giving the effect of making The Doctor’s collar question marks appear reversed.
A novelisation of this story, written by Christopher H Bidmead, was published by Target Books in March 1983. Despite being the first story of the Fifth Doctor’s era, it was not the first novelisation of his era to be published.
The first story of Season Nineteen.
Peter Davison's first full story as the Fifth Doctor.
The first Doctor Who story not to be first broadcast on a Saturday.
The debut of the Fifth Doctor’s cricketing outfit.
The first story in which the lead role is credited as ‘The Doctor’ on the closing credits rather than ‘Doctor Who’ (or ‘Dr. Who’).
The first mention and view of the TARDIS Zero Room.
The first Doctor Who story to feature a pre-credits sequence.
Eric Saward's first involvement in the show as Script Editor.
The first Doctor Who story to be directed by Fiona Cumming.