Dodo frustrates Stephen by being clueless to an almost surreal degree, hopping out of the TARDIS without hesitation into a jungle and thinking she can just hop on a bus back to London. The Doctor actually agrees with Dodo – at least insofar as he thinks they actually are still on Earth somewhere. Dodo, who is at least knowledgeable about animals, notes that the jungle is filled with different species from across the world while the Doctor discovers that there is no sky but a metal roof. The mystery unravels when the Doctor and the others are taken to a group of humans by alien beings, the Monoids. They are told that the ship is a futuristic Ark, taking the human race and samples of all its species away from an Earth that’s slowly being destroyed by an expanding sun to a new world much like Earth, a journey that will take 700 years. The Monoids are an alien race that migrated to Earth long ago from their own dying world and “offered” to become servants in exchange for their new home. Most of the human population has been reduced to a microscopic state and placed in stasis until the ship finally arrives at the new planet, while the humans left active are Guardians, who, along with their descendants, are expected to protect the ship. After figuring out the Guardians’ understanding of time, the Doctor deduces that they’ve wound up 10,000,000 years past the twentieth century.
While most of the Guardians are willing to trust the Doctor and the others, things quickly become tense when a cold Dodo has spreads to the Guardians and the Monoids, who have no resistance because the common cold had been wiped out for millennia. When the chief Guardian is struck down by the illness, the deputy chief, Zentos, has the Doctor and the others arrested and puts them on trial. Zentos accuses them of being sent from the planet they are traveling toward, Rathusis, to sabotage the mission. His paranoid arguments win the day and the Doctor and the others are sentenced to be ejected into space. However, the chief Guardian intervenes and, seeing that Steven is also sick, orders that the Doctor be given a chance to cure the illness but only if he uses Steven as his test subject. The Doctor essentially reinvents the flu vaccine, which stops the plague and of course allows the TARDIS crew to leave as heroes.
However, next they end up landing again in the Ark’s jungle. Dodo finds that a statue the Guardians had started when they left, which was intended to portray a human being, instead depicts a Monoid. They determine that they’ve ended up about 700 years from where they left and that the Guardians are now serving the Monoids. Soon enough, they are captured by the Monoids, who explain that there was a revolution. The Monoid leader, believing that the Doctor was the same one who came centuries ago, goes further and tells them that the flu virus mutated and weakened the Guardians enough for the Monoids to take over. The Monoids force the Doctor and Dodo to go as an advance scout to Rathusis, to see if the Rathusians are hostile. Meanwhile a Guardian discovers that the Monoids are planning to destroy the Ark, with the entire human race inside, once they have a chance to leave the ship with their own people. On Rathusis, the Doctor figures out that the Rathusians are incorporeal beings who welcomed human settlement to the point they actually built cities for them. The Monoid keeping the Doctor and Dodo at gun’s length is killed by the Rathusians, who are needless to say unimpressed by the Monoid’s attitude. Although the Rathusians are concerned, the Doctor convinces them to wait a day for a Guardian uprising against the Monoids before they take “defensive measures.”
Back on the Arc, Steven helps head a Guardian effort to find and defuse the bomb. Luckily, a civil war between the Monoids – those who want to stay on Rathusis despite the danger versus those who want to take the Ark and move on – gives the Guardians a chance to discover that the bomb was hidden in the Monoid statue. The Rathusians are able to remove the statue without causing any harm to the Ark itself. Even after all the trouble, the Rathusians still allow the human race and the Monoids to settle the planet, on condition that they make peace. The Doctor agrees, concluding that the Monoid revolt was driven by resentment at how they were treated like servants by the original Guardians. Later, as the TARDIS flies off, the Doctor disappears, even though Steven and Dodo can still hear his voice, and warns, “This is some form of attack!”
Our Future History
According to this serial, the Earth will be destroyed by the expansion of the sun into a red giant sometime around 10,002,000 AD. Current scientific theory instead posits that this will happen 5 billion years from now (I have no idea if the show’s estimation reflected the state of astronomical theory at the time or if it was a misunderstanding by the writers). The 2005 series episode, “The End of the World,” which likewise takes place at the time the Earth is to be consumed by an expanding sun, reconciles itself with contemporary research into stellar life-cycles by having the year stated to be circa 5 billion AD. The inconsistency between not only the years but the two serial’s similar but largely incompatible premises was actually addressed and explained by Paul Cornell, who basically said, “It was the Time War!”
The Guardians hint that there are other times when at least significant numbers of the human race had to evacuate the Earth. Interestingly enough, this can be taken as a “reference” to the plot of “The Ark in Space”, where humanity in the far future has been driven off Earth by massive solar flare activity, as well as the 2005 series episode “The Beast Below,” which is centered around a similar (and possibly the very same) event as “The Ark in Space.”
They also refer to something called the “Primal War”, during which a great deal of past scientific history was lost.
The idea that the Doctor and the others can transmit foreign diseases to other planets and times is brought up, but dismissed fairly quickly without explaining why it shouldn’t have been a concern in the past – or much of a concern in the future.
I’d also argue that this is the first serial that hints that the TARDIS isn’t teleporting at random at all, but is deliberately leading the Doctor to times and places in need of intervention, which has always been my pet theory (and finally spelled out in the 2005 series’ episode “The Doctor’s Wife”!).
Maybe it’s just the contrarian in me, but unlike seemingly every other Whovian familiar with the First Doctor era, I kind of like Dodo, especially the fact that she spends most of this serial wearing a medieval tunic absconded from the Doctor’s wardrobe. I have to admit I have a soft spot for ridiculously absent-minded characters, being a ridiculously absent-minded character myself, and I would argue in a court of law that the scenes of her reacting to the TARDIS and what it does with a perfect lack of comprehension are actually amusing. Still, even I have to admit that the problem with her is clear, that she’s basically a comic relief character shoved into a starring role. Also it’s a little too obvious that she’s an attempt to make the show appeal to the mod generation, which I can only guess would make her much more grating if I was even halfway familiar with the slang she constantly uses (incidentally, would this make her the Poochie of “Doctor Who”?). On that note, maybe this is me being much too fannish again, but I can’t be the only one who thinks it was out of character for the Doctor to constantly complain about and be so prudish about Dodo’s slang. This is the Doctor who freely admitted to being a Beatles fan, after all…
As for the serial itself, it has a good, fresh premise, both in the Doctor and the companions facing some very nasty consequences from unlimited space-time travel (even if the long-term implications are brushed aside in basically a three-sentence conversation) and in the TARDIS’ crew getting to see how events they helped trigger unfold. The problem is that it actually might have been a better, or at least more unique, serial if we had only the first plot and it had been stretched out to the length of the serial. The second half is basically a recycled version of the plot of “Galaxy 4”: the Doctor encounters tyrannical aliens and gains help from another set of aliens who are at first thought to be hostile but are actually endlessly benevolent (it’s really surprising to see the Doctor happily leave the last survivors of the human and Monoid races in the hands of powerful, bodiless beings who just give him their word that their interests are entirely selfless apart from just seeing bodied creatures running around again; would this have been considered a bit of a plot hole even then or have we become so jaded since 1966?). It all just feels so rote, and while the Doctor gives a speech in the end, pointing out that the Monoids were seeking revenge for the servile status humans had inflicted on them before, it’s too little and too late to inject some complexity and ambiguity into the story.