It was eventually finished three months behind schedule, but the unavailability of several actors for new filming dates forced the production team to recast their parts at short notice.
Initially titled The Enlighteners, her submission involved ships racing through space that, with the addition of the Black Guardian sub-plot, eventually evolved into the story as screened.
[citation needed] The serial was now scheduled to conclude a three-story trilogy featuring the Black Guardian, and Clegg duly wrote the recurring characters into her scripts.
Mills' script was eventually dropped and the production team considered moving The Enlighteners forward in the season to replace it, necessitating considerable re-writes.
Peter Grimwade was eventually commissioned to write Mawdryn Undead to replace The Song of the Space Whale, and The Enlighteners was confirmed as the fifth serial of the season.
[2] It was originally intended that the character of Jackson would not reappear after the second episode, but during filming Saward became concerned that it appeared that he had been executed and so he and Clegg rewrote Part Three to include him.
[5] Lynda Baron was cast as Captain Wrack, having previously participated in Doctor Who in the 1966 serial The Gunfighters as the voice that sings the "Ballad of the Last Chance Saloon" heard throughout that story.
[7] Tony Caunter, who had previously played Thatcher in The Crusade and Morgan in Colony in Space, was given the role of Jackson, with Christopher Brown and David Rhule being cast as Marriner and Wrack's sidekick Mansell respectively.
[3] Similarly to Sallis, David Rhule was unavailable for the revised filming dates in January, so singer Leee John replaced him at short notice, despite having no previous acting experience.
[8] Cumming had originally hoped to simulate the rocking of the ships by mounting the sets on rollers but the idea was dropped due to costs, with the effect achieved by moving the cameras instead.
[1] The photo of Tegan's Aunt Vanessa, one of the items created by Marriner from the contents of her mind, was shot specifically for the filming, requiring Dolore Whiteman (who had played the character in Logopolis) to be contracted for a one-day photoshoot.
[2] The models of the boats, used in the racing sequences, were props sourced by visual effects designer Mike Kelt following extensive research at the National Maritime Museum.
[2] Kelt was shocked by the dilapidated state of the TARDIS console prop, and was worried about damaging it while filming the explosion from Part One, and asked producer John Nathan-Turner if he could replace it but was told there was no money available.
Actor Mark Strickson was injured while filming the scene of Turlough throwing himself overboard, when the Kirby wire he was suspended from broke, leaving him only able to walk with difficulty for several weeks.
[4] By mid-November however the electricians union the EEPTU, had begun strike action which disrupted the filming of a number of BBC productions including Enlightenment and potentially meaning the final three serials of the season would have to be abandoned.
The crew were able to shoot the following serial The King's Demons on schedule, meaning that there was only one recording block left for the part-completed Enlightenment and Eric Saward's season finale; The Return.
[5] With some filming already completed, and its importance in concluding the Black Guardian story-arc, it was decided that Enlightenment should take precedence and so it had its second production block moved to January 1983,[4] while The Return was abandoned.
[7] Writer Barbara Clegg based the Eternals on a wealthy group of her relatives who, upon visiting her, had demanded constant entertainment, treating other family members almost as "lesser beings".
[2] Clegg highlighted the nature of enlightenment, showing it not to be knowledge, as the Eternals believe, but wisdom, as demonstrated by Turlough's rejection of the Black Guardian.
[11] Miles and Wood also highlight the political elements of the story, likening the portrayal of the Eternals to the view of the upper classes as "effete parasites feeding off the labour (and in this case the imagination) of the proles."
[2] Reviewing the story for Doctor Who Magazine's 200 Golden Moments special edition, Jeremy Bentham described it as being epic in scale, suggesting it played to the original strengths of the series; "performance, period set design and claustrophobic mood".
[15] Writing for the Radio Times, Mark Braxton was less enamoured of some of the performances, suggesting that Baron and Valentine Dyall turn in 'hammy' interpretations of their characters, while Leee John "makes heavy weather of the simplest activities: helming the ship seems to require the most bizarre posturing."
[19] A novelisation of this serial, written by story author Barbara Clegg, was published by Target Books in May 1984, with a cover by Andrew Skilleter, and was numbered 85 in the ongoing range.
[20] On its publication Doctor Who Magazine was underwhelmed by the book, claiming in their review that "In many ways, it falls into the familiar Terrance Dicks pitfalls, being a straightforward reworking of the script with "said" following all the speeches.