The TARDIS lands, or more like crashes, on the moon instead of Mars. While Jamie is stunned at being on the moon “way up in the sky”, Ben and Polly convince the Doctor to let them wear spacesuits out and go sightseeing. Polly keeps thinking she’s seeing a blur out over the lunar surface, but she becomes quickly convinced that it’s nothing, and Jamie gets a head injury while playing around in the moon’s low gravity. The Doctor and the others stumble across the titular moonbase, where one of the crew has been found unconscious from a mysterious infection, and bring Jamie in for treatment, claiming that they just arrived on the moon via a routine spacecraft. The Doctor surmises that they’re on a station that uses a device called the Gravitron to control the Earth’s weather (explaining why the TARDIS crashed) and that it’s 2050, although the station’s manager, Hobson, corrects him by pointing out it’s actually 2070. When the Doctor introduces himself, Hobson drafts him to investigate the cause of the mystery illness that’s been striking down members of the crew, since the base’s sole doctor has been one of the victims.
While overseeing the patients, the Doctor notes that the symptoms of the illness don’t match up with any human disease he knows of. The base’s doctor dies, his delirious last words about a “silver hand”, while one of the crewmembers suddenly disappears. Jamie and Polly see a Cyberman, its body sleeker and more metallic than when the First Doctor encountered them, but it vanishes with one of the patients. Hobson refuses to believe it, saying that the Cybermen had been wiped out many years ago, and instead accuses the Doctor and his crew of being behind things. Still, the Doctor convinces Hobson to give him 24 hours to cure the mystery illness. Meanwhile the base’s crew try frantically to stop a hurricane from getting out of control. When another crew person becomes sick after drinking coffee, the Doctor realizes that the base’s supply of sugar had been infected with a virus that attacks the nervous system deliberately introduced by the Cybermen, a theory that finally convinces Hobson.
When Hobson and the TARDIS crew try to find where the Cybermen are hiding, they reveal themselves, and claim that they have been “converting” the sickened men. It turns out that since the destruction of Mondas the surviving Cybermen have deemed Earth as a “danger” and plan to use the base’s weather manipulating capabilities to wipe out all life on Earth. Holding the base’s crew captive, the Cybermen have the base’s equipment operated by the crewmen they had captured, infected, and brainwashed. Elsewhere Polly, inspired by Jamie’s comment that in his day they sprinkled holy water on witches, decides to try using a cocktail of solvents on the plastic unit the Cybermen have in place of their hearts and lungs. Back in the control room, the Doctor manages to figure out that using the equipment in the control room to create audio feedback interfered with the Cybermen’s control over the men and puts his discovery into practice, just before Ben, Polly, and Jamie kill the Cybermen with the solvent cocktail. The infected men are freed from the Cybermen’s control (or so it seems) and put in the medical room. All seems clear, but from a telescope the Doctor looks on horrified as the rest of the Cybermen march toward the base across the surface of the moon.
The Cybermen jam the base’s communications with Earth and manage to get the infected men back under their control. Worse, an infected crewmember uses the Gravitron to deflect a relief rocket sent from Earth toward the sun and the Cybermen use a laser weapon to breach the oxygen shields of the base, although they’re able to seal the breach with a coffee tray. The sudden lack of oxygen does knock out the infected crewman, letting the crew get control of the Gravitron again. Under the Doctor’s directions, the crew uses the Gravitron to hurl the Cybermen and their ships toward the sun. After leaving the base’s crew to try to fix the damage to Earth’s weather patterns caused by the Cybermen, the Doctor decides to use a “time scanner” (which he admits is not very reliable) to get a preview of their next destination, and all he sees is a giant crab claw…
Sign of the Times
Again, Polly makes coffee for all the men…twice.
Ben refuses to let Polly try to use the solvent cocktail on the Cybermen, saying, “This is men’s work!”, although Polly does refuse to obey.
Our Future History
By at least 2050, humanity will have discovered how to control gravity and how to use that control to technologically regulate the weather. Plus space travel to the moon will have become so commonplace that even the crew of a moonbase will be unfazed by having unexpected visitors.
The Doctor claims to have earned a medical degree in 1888 after studying at the University of Glasgow under Joseph Lister. Polly understandably thinks this makes the Doctor’s medical knowledge a tad outdated.
The official Discontinuity Guide labelled The Moonbase as “boring,” which I think is a bit unfair. It doesn’t really have any memorable Doctor or companion moments (in fact, Jamie is out of action for about half the serial, since the decision to make him a companion was a last-minute one and there wasn’t much for him to do in the script as originally written) and it keeps up the “mystery” of the strange illness even after it’s obvious the Cybermen are behind everything. However, the last episode at least is genuinely thrilling. The fact that the basic set-up to this serial will be rehashed many times through the Second Doctor era (enough that, as Diamanda Hagan helpfully points out, “An isolated base under siege” is to the Second Doctor what “The Doctor working with UNIT against covert alien invaders” and “Massive alien invasion of contemporary London” were to the Third and Tenth Doctors respectively) is honestly a testimony to the fact that something about this serial worked, even if at the same time its set-up is conveniently budget-friendly.
Also it’s the first time we see the Cybermen in anything resembling the incarnation most people are familiar with. To be honest, I preferred the way they looked in The Tenth Planet, since it gave more the impression of designer cyborgs fashioned by a desperate people on the brink of extinction, but I can also see why the cold, mechanical look of the “new” Cybermen has endured in its place. The Cybermen still aren’t my favorite Who villains, but I will admit that the scenes of them marching calmly across the barren wastes of the moon were pretty epic. All in all, it’s not a classic, apart from what is arguably the first “familiar” appearance of the Cybermen, but it’s not the dud some commentators have made it out to be.