Mawdryn Undead has long been one of the most popular stories of the Davison era of Dr. Who. Its success lies partly in the way that it takes themes and characters that are very familiar to anyone who has watched the series for a number of years, and combines them with some fairly radical departures from the norms of the series plotting and characterization.
One of the most obviously familiar elements of the story is the presence of Brigadier Lethbridge-Stewart. It seems very natural, that in a story made for the series 20th anniversary season, a character who has played such a big role in the programmes history should return, and it is a return to form as well. This Brig is very clearly the intelligent military man of the early Pertwee stories, not the frankly daft blunderer of The Three Doctors (what were you thinking of Bob and David?). That said, this is no return to UNITs glory days, as we discover the Brig teaching maths in a school, and suffering from amnesia brought on by some kind of nervous breakdown. Courtney plays both versions of the Brig very well here, and his vulnerability over his missing memories is very touchingly played, reminding us that any display of emotionalism must be hard for this old soldier. Some have said that the inclusion of the Silver Jubilee crates a problem with dating the UNIT stories. I have always assumed that they were contemporary, and so, to my mind, this doesnt present a problem.
Mawdryn Undead also sees the return of Valentine Dyall as The Black Guardian. Dyalls portrayal of the character is quite entertaining, but The Black Guardian is, essentially, a pantomime villain, spending much of his time snarling at Turlough and threatening death and destruction at every possible opportunity. Im almost tempted to boo and hiss every time he appears on screen. The rather strange choice of costume (this is an ex parrot) doesnt help. In the hands of a less charismatic actor, this would all be very embarrassing, but Dyall somehow rises above the limitations of role and apparel, to give a performance that is, at times anyway, quite scary. The much discussed issue of why The Black Guardian can not be seen to intervene directly to destroy The Doctor is one I can not attempt to answer definitively, but perhaps it would incur the wrath of The White Guardian.
Having dealt with the return of two previously seen characters, its time to talk about Turlough. Personally, I like the character, and I like Stricksons performance. This is one of the areas where Mawdryn radically departs from the norms of the series. Of course, were used to seeing companions becoming caught up accidentally in the Doctors affairs, and deciding to stick around ( cf. Jamie, Sarah, Leela etc. , etc. ) , and companions who are kidnapped or unexpectedly removed from their own time ( Ian, Barbara, Tegan ) , but there has never been a companion who became involved with The Doctor because he was trying to kill him! He is also one of the few companions that it is hard to feel real affection for. Usually, the occupants of the Tardis are a pretty pleasant bunch. Strickson, in the opening moments of this serial, establishes Turlough as a sneaky, cowardly, cold young man, and, although his time with The Doctor mellows him a little, these essential traits remain in place until he leaves, under something of a cloud really, at the end of Planet of Fire. During this serial, Strickson starts the process of taking turlough from his starting point as a quite unpleasant individual to someone who begins to appreciate the values and actions of someone like The Doctor. Sticksons performance is one of the joys of Mawdryn Undead. Of course, it was this dwelling on the interaction of characters in the Tardis crew that lead Andrew Cartmel to describe this era of the show as Neighbours with roundels, which I cant help feeling not only ignores one of the things that made the early Hartnell series so compelling, but also seems a bit hypocritical from the man who gave us the Grange Hill with explosives character of Ace. At least in the Davison years, character development wasnt done with a sledgehammer.
The plot of Mawdryn Undead also deals with a theme that is very familiar to long time fans of the series, that of scientists using their knowledge for questionable ends. We can see this theme in evidence in stories such as The War Games, The Brain of Morbius, Robot, Invasion of the Dinosaurs etc., etc. . . . Here, immortality is the goal sought by Mawdryn and co., and this is the first of two occasions in season 20 that immortality is seen as something craved by villains, the other occasion being, of course, The Five Doctors. However, Mawdryn is not a straightforward villain, and, rather like Omega in Arc of Infinity, we do feel some sympathy for him. This traditional bad scientist plot is given a twist by a quite surprising use of The Doctors ability to time travel. Tegan and Nyssa become stranded in 1977, while The Doctor is in 1983, both parties encounter The Brigadier, and it the eventual meeting of these two versions of The Brigadier that causes the release of energy that provides the plots resolution. This makes time travel central to the plot, rather than simply being the device by which The doctor and his crew enter the story. There have, of course, been stories where time travel has played a role in the plot ( The Chase, Earthshock, Pyramids of Mars, etc. ) , but in Mawdryn it plays a very central role, explaining The Brigadiers breakdown, and providing the resolution. Given the unpredictability of The Tardis when piloted by the Fifth Doctor, it also raises the possibility of The Doctor being separated from his companions permanently, especially as it went with them and not him!
Any mention of time in this story will inevitably lead into the long standing argument over whether this story plays fast and loose with the UNIT continuity by showing a Brigadier who has retired from the organization by Summer1977 at the latest. I have to say, I dont think this argument can ever be resolved, as, when it comes to dating the UNIT stories, there is a lot of contradictory evidence in the series as a whole ( not least of all Sarahs claim in Pyramids of Mars that she comes from 1980 ) . I am content to accept that the majority of the evidence tends to suggest that the UNIT stories were more or less contemporary, and that Mawdryn Undead doesnt really present a problem in continuity terms.
All in all, this is one of the best stories of the Davison era, and I would be very surprised if it doesnt remain a firm favorite with fans for many years to come.