The Ark
Most of the Hartnell Doctor Who stories that I consider to be overlooked by fandom are either wholly or partial missing from the archives; the exception to this rule is 'The Ark'. Even with its recent video release, it is seldom talked about either fondly or with contempt, although exactly why this should be is not entirely clear. My best guess is that, quite simply, 'The Ark' is an oddity.
The direction and design of 'The Ark' is exemplary. There are numerous shots that impress, including the take-off of the landers from the Ark, and most notably, the scenes of the invisible Refusian moving objects around, which are incredibly well done. The interior of the Ark is also very impressive, meshing futuristic sets and model work with ease. The giant statue is the best example of this, as the camera switches from shots of its feet to panning shots up the model. The jungle too is excellent, and made all the more convincing by the presence of real animals, especially the elephant. The castle on Refusis II is another effective use of model work, again meshing well with the countryside sets of the planet's surface. The only visual aspects of the production that has aged badly are the space shots, with wobbly landers on strings, an unconvincing nuclear explosion, and a truly dreadful shot of the Earth burning up. The Monoid costumes are another triumph, with the creatures numbering amongst the most convincing aliens of the era. This is largely due to their single eyes, which are achieved by the actors holding them in their mouths and moving them with their tongues. Compare this with the later appearance of Scaroth in 'City of Death', which is far less convincingly achieved. This, and their mop-top hair, makes their appearance much more memorable than generic reptilian alien. Sadly, the human Guardians fare less well, boasting the most absurd costumes of any humanoid characters in the series up until this point, including the Thals; they look very much like a kitsch sixties vision of the future, which I suppose they are, and have aged very, very badly.
The plot of 'The Ark' is its greatest strength, due to the novelty structure it adopts, effectively being two two-part stories back to back. The first two episodes are basically the build-up, but form a tight drama in their own right; the concept of the Ark carrying the last survivors of humanity to an new world is a good one, and initially appears to be a typical science fiction portrayal of an advanced utopian future society. However, the cracks in the veneer are soon exposed, as Dodo's cold infects the Ark's inhabitants and threatens their future; paranoia and suspicion become rife, and the seemingly peaceful Guardians are soon out not for justice, but for retribution (they want the travelers banished from the Ark, but won't allow them to leave in the TARDIS; instead, they refuse to accept that Dodo brought her cold to the ship by accident and demand that they be ejected into space, and thus executed, as punishment for their crimes). But there are other, subtler, hints that this human society is less advanced than it seems. When Dodo's cold causes an outbreak, they suspect that the travelers are agents from Refusis, their chosen destination, trying to prevent their colonization of that planet; this immediately suggests that the Guardians are determined to colonize the planet whether the native inhabitants like it or not. More importantly, they claim that the Monoids are their friends, and seem to genuinely believe this, but the Monoids clearly form a second class of citizen, occupying the menial tasks on board the Ark. Most tellingly, when the occupants of the Ark become sick, Zentos notes that the Monoids are starting to die, and then adds that it will be really serious if a Guardian also dies, immediately demonstrating the relative importance ascribed to the two different populations by the Guardians. The pay-off for all this comes in episodes three and four, when the Monoids have taken over and the Guardians are reduced to the role of slaves, the Doctor noting at the end that their rebellion is hardly surprising and that both races must learn to live together on an equal footing. Incidentally, the cliffhanger ending to 'The Plague' is another example of a cliffhanger that, whilst still impressive, must have had far more impact on its first broadcast, as the TARDIS returns to the Ark and the travelers discover that the huge statue has been completed and has the head of a Monoid. Even with foreknowledge, it is still a classic moment.
William Hartnell and Peter Purves once more deliver on the acting front, with the Doctor seeming more of a wise bystander than on previous occasions. He seems less cantankerous than usual, and is determined to help the inhabitants of the Ark. His frustration at not being allowed to try and cure the cold unleashed by Dodo is palpable, as is his delight when he succeeds in doing so. His forgiving and understanding attitude towards Zentos' earlier rabid desire for vengeance is admirable, and he is gracious when he accepts the deputy commander's apology. In the second half of the story, he continues his active role in resolving the situation, speaking on behalf of the Ark's passengers to the rather likeable Refusian, and generally mediating between various parties; it is the Doctor who at the end tells the humans that they must make peace with the Monoids, a sentiment with which the Refusian agrees on as a condition to both races staying on Refusis II. Throughout the series thus far, we have often seen the Doctor deal smugly with villains, only to be suddenly brought up short when they gain the upper hand (the Daleks are the most obvious example, but others range from Lobos, to the Animus, to Nero); it makes a refreshing, and indeed amusing, change, to see the Doctor's obvious contempt towards Monoid 1, whom he speaks to with condescension and sarcasm. There is no particular lesson to be learned from this, but it is highly entertaining. Steven is on fine form as usual, seething with righteous anger during the trial in 'The Plague' and denouncing the supposedly advanced Guardians as no better than their primitive ancestors. During 'The Return' and 'The Bomb', he plays a crucial role in the enslaved Guardians' rebellion, hinting for the first time at hitherto unseen leadership skills, a character development that rises quite logically out of his frustration at being unable to help those around him during 'The Massacre of St Bartholomew's Eve'. And then there's Dodo.
As a new companion, Dodo fills the young-female-sidekick-for-the-Doctor-to-explain-things-to role, previously occupied by Susan and Vicki (and, briefly, Katarina, although Sara Kingdom rather broke the mold). Since it is her cold that almost wipes out the human race, she is immediately given an active role, which is good way to introduce a new companion, and she immediately comes across as likeable enough, in large part due to the compassion and guilt brought out by the tragedy she unwittingly caused. Sadly, this doesn't last, and in the last two episodes she does very little, not even reacting very much to the revelation that her cold contributed to the success of the Monoid revolution. Nevertheless, I'm not sure why she is quite so reviled by fandom as she is, although her sporadic cockney accent doesn't do her any favours.
Unfortunately, because of the structure of the plot, there is little for characterisation of the supporting characters in 'The Ark'; the Guardians are two-dimensional, but the Monoids are even worse. Monoid 1 gets the most lines, but he's portrayed as a stock megalomaniac, to such an extent that he actual gloats almost constantly. In fact, the best-characterised supporting character is the Refusian, and even he gets little to do, although he comes across as considerate, thoughtful and intelligent. Nevertheless, 'The Ark' manages to remain interesting throughout, and its unusual structure and excellent production standards compensate for its shortcomings. It isn't a classic, but it is a solid story and undeserving of its relative obscurity.