The final story in the Black Guardian trilogy, 'Enlightenment' is very good. The concept of a race in space is not that original, but the idea of having the ships involved be replicas of sea ships from different periods of Earth history is inspired and makes for a memorable story. With the unusual nature of the aliens responsible for the race also central to the plot, the overall result is a story that feels like it's trying to be something special, and largely succeeding.
The concept of the Eternals' need for Ephemeral minds to relieve the boredom of eternity means that writer Barbara Clegg is able to build a story around what is essentially a yacht race in space without it seeming contrived, but it is also an interesting idea in it own right. The Eternals' are memorable not just because they use sailing ships in space, but also because of the way they interact with the regulars. Marriner is the most obvious example; Christopher Brown's performance is initially deeply sinister, his obsession with Tegan seeming utterly predatory. During Episode One, and prior to the revelation of the Eternals' true nature, his intense interest in her seems sexual; his claims that he wants to please her rather than hurt her are not reassuring, they are horribly unsettling. Once the nature of the Eternals becomes clear Marriner's true motivation is revealed, but the disturbing parallels remain; in Episode Two he drugs her and then searches through her mind telepathically - it could easily be argued that this is a form of rape, and Tegan certainly considers it a kind of violation. Interestingly however, as the story progresses, Marriner's relationship with Tegan changes; she remains wary of him throughout, but it becomes clear that he really won't hurt her, and it is particularly interesting that the Doctor trusts him to look after her whilst he goes to rescue Turlough on board the Buccaneer. The effect of all of this isn't that Marriner is especially likeable by the end of 'Enlightenment', but instead that he ceases to be sinister and instead becomes rather pathetic, like a slightly frightening but harmless celebrity stalker who sends endless love letters to his or her idol.
Christopher Brown's Marriner however is not the only Eternal of note. Keith Barron's performance as Striker is very effective, because he brings an impassive air to the role that makes it easy to believe that Striker is utterly inhuman. Striker acts almost as a spokesman for the Eternals, since he is used to reveal their nature to the Doctor and thus to the audience, and it proves a good choice. Barron's flat, almost disinterested, tone of voice conveys the nature of the Eternals beautifully; they are arrogant, but it is an arrogance born simply out of what they see as their natural superiority; they can control matter and they will endure forever. Their casual acceptance of the deaths of those Ephemerals killed by Wrack's destruction of her competitors is not the lack of concern for others demonstrated by, for example, the Master, but is instead born out of an inability to understand the importance of what to them is such a miniscule span of life. Barron brings this across extremely well, in addition to which he also creates a sense of boredom in Striker that emphasizes the fact that the race is merely a short diversion for him.
Then there is Captain Wrack, played with considerable gusto by Lynda Baron. Baron's performance is almost over the top, but she gets away with it for the most part because as an Eternal who draws on Ephemeral minds to give herself shape and purpose, the portrayal of Wrack as a clichéd pirate captain is entirely appropriate. The decision to make Wrack female also helps; female villains are rare in Doctor Who, and this means that although Wrack is something of a cackling megalomaniac, she feels sufficiently different from the norm to be interesting. Having said that, the cliffhanger to Episode Three, when Wrack breaks the fourth wall and looks into camera, slightly undermines the proceedings, especially when Wrack rolls her eyes and then cackles; for some reason, by looking into camera Baron makes herself seem too over the top, rather than just enough. Nevertheless, Wrack works well as a one-dimensional villain whose very nature limits the potential for complex motivation. Whilst I'm on the subject of villainous Eternals, I should get mention of Mansell out of the way; possibly the worst actor ever to appear in Doctor Who, third-rate pop singer and recent participant in the vacuous "reality" TV show Reborn in the USA, Leee John is so bad that it is phenomenal. It is almost inconceivable that he ever got cast; his stilted, self-conscious, and just plain bad performance is the only real weakness of 'Enlightenment'. Mansell is not prominent enough to really spoil the story, but even so every other performance is so much better than his that it makes it noticeably cringe worthy. Even the actors playing the sailors in Episode One, who get very few lines, manage to show John up.
The regulars are all very well used in 'Enlightenment'. Peter Davison gets one of his finest moments in the role as the Doctor argues passionately with Striker, enraged by the parasitic nature of the Eternals and seeming genuinely angry. Perhaps more interesting however, is his relationship with Turlough; the Doctor is noticeably rather tense around Turlough for the first two episodes, but this changes after his panic-stricken suicide attempt at the end of Episode Two. What is particularly interesting is that it is never explained whether or not the Doctor realises that his new companion has been working for the Black Guardian for some time. There are hints; he doesn't trust Turlough to await further messages from the White Guardian, and he doesn't seem remotely surprised when Turlough's contract with the Guardian is discussed at the end of the story. Indeed all he says about it is that he believes Turlough when he says that he never wanted the agreement in the first place. The finale of the Black Guardian storyline is very well handled and Strickson puts in a fine performance throughout; it is clear now that he will not kill the Doctor, with this ultimately resulting in him throwing himself overboard because he won't obey the Guardian. Even more interesting is the scene in which Turlough is trapped in Wrack's power room with the vacuum shield switched off - he stops asking the Black Guardian for help, and instead screams out for the Doctor. The final scene with the Guardians is very well staged, Turlough staring at the diamond and weighing up power and fortune against the Doctor's life; his final rejection of the Black Guardian completes his slow redemption. It is interesting to watch the Doctor during this scene as he simply stands quietly and waits for Turlough's decision; his calm attitude suggests that he already knows what Turlough's choice will be.
As I've already noted, Tegan too is used well in 'Enlightenment', as she is forced to deal with Marriner's stifling attention. Janet Fielding alternates between anger and vulnerability very well, and shows Tegan forced to deal with an unusual and frightening situation very well. She also conveys Tegan's gradual realization that Marriner isn't actually going to hurt her rather well, as the script calls for her to start arguing with him about the Eternals' use of Ephemerals for entertainment and about the fact that her thoughts are private. It is this gradual acceptance that Marriner won't harm her that allows Tegan to enjoy getting dressed up for Wrack's reception and after two episodes of being frightened, exploited, or seasick, it's nice to see Tegan smile. Her relationship with Turlough is also complete by the end of 'Enlightenment'; she still seems to consider him unreliable, but they have reached a point where they can travel together in the TARDIS, and the chess scene at the start of the story shows that their cooperation during 'Terminus' has resulted in a tentative friendship.
The Guardians are well used in 'Enlightenment', nicely rounding off the Black Guardian trilogy. The return of Cyril Luckham to the role of the White Guardian, now complete with dead pigeon, nicely rounds off the trilogy by reintroducing the Black Guardian's opposite number. It is rather fine to see both Luckham and Dyall together in the final scene, as the two Guardians discuss the race; in keeping with the idea that the Guardians maintain the balance of the universe, there is no feeling of actual enmity between them. Instead, the Guardians are portrayed as opponents in a game of universal chess, their argument about light and dark, order and chaos, taking the form of a political discussion between two wily old men. Both Luckham and Dyall bring great dignity to their roles, but at the same time Dyall recaptures the malevolence of his role, whilst Luckham brings an air of calm benevolence to the White Guardian. Turlough's choice, and the fact that flames consume the Black Guardian, brings a satisfying air of closure to the storyline that started in 'Mawdryn Undead'. Despite the White Guardian's warning that the Black Guardian will return, this marks his final appearance in the television series (and he hasn't appeared in any novels or audio adventures set after 'Enlightenment') and it stands as a satisfying end to the battle of wits between the Doctor and one of the series' most unusual villains.
In addition to all this great acting, plotting and scripting, 'Enlightenment' looks great too. The sets are very well realised and capture the period feel of the appropriate ships very well. The model work generally looks very good, although the rescue of Turlough in a big net looks poor due to the perspective being wrong. Fiona Cumming does a great job of directing, creating striking visual imagery throughout especially during Wrack's attempt to destroy Striker's ship. My only slight criticisms of the production are the silly neon sign proclaiming that the vacuum shield is off, and Malcolm Clarke's intrusive incidental score. Clarke's score is particularly irritating during Wrack's party, at which point it sounds like what it is - a feeble attempt to recreate music from the appropriate period using an electronic synthesizer. But this a minor complaint and overall 'Enlightenment' stands up as a fine Doctor Who story and one of the highlights of Season Twenty.