I noted when I reviewed 'Robot' that Terrance Dicks is not my favourite Doctor Who writer. Whilst I stand by this comment in general, I regard 'The Brain of Morbius' as the highlight of his Doctor Who career, and the success of this story is perhaps therefore due to the fact that Robin Bland is not, in fact, Terrance Dicks, but Terrance Dicks heavily script-edited by Robert Holmes. 

'The Brain of Morbius' is of course heavily influenced by Frankenstein, and in many respects feels like a homage to Hammer Horror. This results in a distinctly gothic feel to the story, which is unusually horrific even for this period in the series' history. The opening scene of Kriz the Mutt being beheaded by Condo sets the tone, and this is followed by Kriz's twitching head being wired up by Solon, the discover of the headless but obviously living Morbius monster at the end of Episode Two, the revelation of Morbius's brain floating in a tank, Condo's bloody and graphic shooting at the hands of Solon, and the grotesque sight of Solon gingerly cradling Morbius's brain in Episode Three. In addition to which we have the Sisterhood carrying out human sacrifice. This macabre atmosphere typifies 'The Brain of Morbius' and is crucial to its success; the entire story is set on an alien planet, but it could just as easily be set in a Hammer Horror version of Transylvania, with a gothic castle atop a bleak and rocky mountain, a mad scientist, a hunchbacked manservant, and a local coven of witches in the form of Sisterhood. 

The actual plot of 'The Brain of Morbius' is very simple; Solon wants the Doctor's head in order to house Morbius's brain and the Doctor is understandably reluctant to surrender it. Solon thus spends most of the first three episodes chasing after the Doctor, whilst he is alternately hindered and helped by the Sisterhood of Karn. By Episode Four, Morbius once more has a body and the emphasis changes as the Doctor, Sarah and the Sisterhood strive to destroy him. Whilst this plot is sound enough in its own right, what really makes it work is the exemplary characterisation and acting. Philip Madoc almost steals the show as Solon, playing a mad scientist without succumbing to the temptation to go over the top. Whilst Solon is undoubtedly insane, Madoc plays him with such pathos that we see numerous different aspects of his personality. Most overwhelming of course is his obsession with Morbius, and obsession, which has, as he himself notes in Episode Three, forced him to spend years in desperately lonely isolation. His absolute devotion to Morbius drives him completely, everything he does motivated purely by his need to complete his work. As played by Madoc he is nervous and twitchy, impatient to find a head for Morbius's brain, and this results in an air of wild eyed but restrained of mania. But Solon displays other attributes too; he's short-tempered, most notably with Condo, and when enraged he resorts to physical violence, cuffing his servant around the head and eventually shooting him. But he's also largely a coward, and it is thus his obsession with Morbius alone that drives him to desperate measures. When Solon realsies that the Sisterhood have "rescued" the Doctor, he rants and raves, describing them as "a squalid brood of harpies", and when he reaches their temple and discovers that they intend to sacrifice the Doctor, his desperation to obtain the Doctor's head drives him to dare to interrupt the ceremony. However, once his adrenaline rush wears off, he realises his folly and panics; when he pleads with Maren for the Doctor's head he babbles in obvious fear, offering Condo instead out of shear desperation. Indeed, his desperation is such that in addition to endangering himself by risking the wrath of the Sisterhood he comes close to blurting out his reasons for wanting the Doctor's head, thus also endangering Morbius. In addition to his humiliating failure, he also pushes Condo too far, resulting in his near death back at his castle, as Condo angrily pulls a knife on him. With little other option, he is then forced to offer Condo his other arm back, a promise he has no intention of keeping; this further complicates matters for him, as he needs to find a way of stalling Condo as a result. 

It is this deeply flawed persona that makes Solon work so well as a character, and there are other examples throughout. In Episode One, when the Doctor and Sarah first arrive, Solon is at his most charming as he grasps the opportunity presenting itself, but despite the effort he makes, his desperate obsession means that his charm barely covers his grotesque intentions for the Doctor's head and he comes across as decidedly creepy, as Sarah very obviously notices. Ironically, it seems that despite Solon's total devotion to Morbius, Morbius himself has little regard for Solon; Morbius's paranoia and rage whilst trapped in his tank is understandable, but it is worth noting than when he is finally properly installed in his new body, he casually discards the corpse of the newly deceased Solon, despite the fact that he has Solon to thank for his resurrection. It is perhaps fitting that Solon dies just as he completes his life's work. 

Morbius too is well characterised. Whilst trapped in his tank, he sounds desperate and paranoid, and Michael Spice's voice conveys some of the horror of his situation very well. Once Morbius is released however, he changes, becoming both confident and arrogant as he confronts the Doctor in Episode Four. For all that the Doctor and Maren describe the threat posed by Morbius, most of 'The Brain of Morbius' essentially revolves around a very localized threat to the Doctor and Sarah; nevertheless during the brief period in which Morbius is housed in his new body and is lucid, Spice manages to create sufficient charisma for Morbius to make it believable that he could rouse an army to threaten the entire galaxy. Appropriately, Morbius's confidence proves his undoing, as he accepts the Doctor's challenge of a mindbending contest, and pays the price. And the sight of Morbius's brain almost literally blowing a fuse is strangely disturbing as his brain case fills with smoke. 

Contributing to the atmosphere of 'The Brain of Morbius' is the Sisterhood of Karn, who despite ending up on the same side as the Doctor in the fight against Morbius is by no means particularly friendly. Whereas Solon is motivated by his obsession with Morbius to commit murder, the Sisterhood are motivated by their jealous possession of the Elixir of Life to commit atrocities that are at least as bad. So paranoid are they about guarding the Elixir and their Sacred Flame that they drag ship after ship to its doom, regardless of whether those ships are headed for Karn or of what their occupants intend. On first discovering the Doctor's presence on Karn, Maren assumes the worst and decides to burn him alive; in short, the Doctor's only allies on Karn are not nice people, and this adds to the general sense of danger in 'The Brain of Morbius'. As with Michael Spice as Morbius and Philip Madoc as Solon, Cynthia Grenville as Maren puts in a great performance, alternating between imperious and unforgiving in the first two episodes, and later showing a more vulnerable side, as the Doctor's criticisms of the unchanging Sisterhood hit home and she shows the weariness one might expect after centuries of stagnation. The Doctor's effect on the Sisterhood is quite profound, as his constant gentle mockery gradually has an impact not only on Maren but also on Ohica. By the end of the story there is a suggestion that the long-unchanged Sisterhood has been affected not only by Morbius's brief return, but also by the Doctor, and that there is hope that they will, if nothing else, at least stop hijacking passing space travellers and killing strangers without discrimination.

By this point in the season, it almost goes without saying that Tom Baker and Elizabeth Sladen are excellent, but it is worth noting that 'The Brain of Morbius' is a particularly good story for Sarah. Unusually, all three cliffhangers revolve around Sarah instead of the Doctor, and of course she also gets blinded, a situation with allows Sladen to shine as she conveys a sense of barely restrained panic. Sarah is also frequently terrified here, encountering headless monsters and being forced to assist Solon in his brain transplant operation in Episode Four, unable to see and under threat of death. When Condo grabs her by her hair in Episode Three she is again clearly terrified, this giving way to revulsion as Condo shyly tells he likes her. When he saves her from the monster in Episode Four but is killed in the process, she sounds suitably guilty, as she struggles with the fact that Solon's hulking manservant has saved her life at the cost of his own. Of all the supporting characters in 'The Brain of Morbius', Colin Fay's Condo is arguably the most sympathetic; whereas Solon commits atrocities out of obsession and the Sisterhood commit murder out of jealous possessiveness, Condo kills (at least as far as the audience knows) because of Solon's hold over him; Condo wants his arm back. This doesn't excuse him, but in a story filled with characters who are on very dubious moral ground, Condo's actions are marginally more justifiable. His attraction to Sarah also adds to his character, in an amusing nod to The Hunchback of Notre Dame. The Doctor also shines, on the one hand at his wittiest when dealing with the Sisterhood (to Maren's obvious annoyance), on the other at his most intense when dealing with Morbius and Solon; his decision to resort to using cyanide gas to try and stop Solon is testament to how dangerous he considers Morbius and shows him at his most committed.

Production wise, 'The Brain of Morbius' is exemplary. It's very well directed, the score is marvelously evocative, and the sets are superb, especially Solon's castle. Also worth mentioning is the rocky landscape of Karn, which is one of the series better rocky landscape sets. The costumes are also very effective, from the elaborate flame-decorated robes of the Sisterhood to Solon's understated tweedy suit. The Morbius monster is particularly impressive, managing to look like it is made of alien body parts whilst still successfully looking like a piecemeal abomination rather than an actual alien creature. Overall, 'The Brain of Morbius' is a highly effective if unusual story, and after the dreadful 'The Android Invasion' it marks a return to the generally high quality of the season as a whole. A level of quality that will be maintained for the season finale…

Terry Nation is possibly Doctor Who's most erratic writer. On the one hand he is capable of writing classics such as 'The Mutants', 'The Dalek Invasion of Earth', 'The Daleks' Master Plan' and 'Genesis of the Daleks', whilst on the other hand he is capable of writing such balderdash as 'The Keys of Marinus', 'The Chase', 'Planet of the Daleks', and, unfortunately, 'The Android Invasion'. Apologists for this story might argue that it seems worse than it is alongside the other stories of Season Thirteen, but personally I think there's so much wrong with it that placing it next to any other story, no matter how dire, is going to amount to little more than trying to polish a turd. 

'The Android Invasion' suffers from more plot holes than any other Doctor Who story I can think of. First of all, we have the replica of Devesham on Oseidon. This is immensely detailed and extremely elaborate, which raises the question, what exactly is the point of it? To explain what I mean, allow me to recap Styggron's plan. The Kraals intend to invade Earth and wipe out mankind using a virus. The virus isn't airborne and it kills its victims within seconds or minutes, which would limit its spread immediately, since anyone infected with it wouldn't have time to travel very far before dying. Metres, if they are lucky. Therefore, Styggron's androids are intended to "disseminate" the virus. In addition, note that Styggron insists that the extermination of mankind will take place within three weeks. Therefore, the androids will have to transport the virus to all parts of the planet within that time and physically expose everyone on Earth to it. This is, clearly bollocks; firstly, there are only a handful of androids, and secondly as soon as whole areas started dying in one go, quarantines would be enforced. Since there is no evidence that Styggron has facilitates on Earth to make new androids, this means that a group of androids who resemble the inhabitants of one small village are expected to evade quarantines without being noticed, which is also bollocks, and in case anyone is thinking of pointing out that they are allegedly indestructible, allow me to point out that this is twaddle, since Sarah electrocutes one (and their faces fall off very easily if they trip up). Even if we assume that this is possible, the androids would still have to spread out from Devesham on arrival, which raises the question of why Styggron establishes an elaborate program of training that involves the androids spending an afternoon in the local pub. The point is, the only possible reason for the needlessly elaborate Devesham mock-up would be if the Kraal androids were intended to infiltrate Devesham by replacing the inhabitants and then spend some time there gathering information. Which they aren't. Indeed, not only that, but they successfully replace the entire personnel of the Space Defence Station within minutes of arriving. The only remotely plausible explanation that is actually consistent with the witless plot is that the training ground allows them to become familiar with the layout of Devesham and the Space Defence Station, which in any case is provided to Styggron by Crayford. Some kind of map might have been easier…

In addition to these gaping plot holes, if Styggron wants to use the androids to wipe out mankind, why doesn't he just drop androids all across the planet from orbit, instead of bringing them all to Devesham? If he's so clever, why doesn't he just create an airborne virus? If he can't, why doesn't he just fill a couple of pods with the virus and dump it in the ocean, since Nation appears in any case to have misunderstood the difference between the words "virus" and "poison". The number of unanswered questions in this story are astounding; if the brain patterns taken by Styggron from humans are as detailed as he implies, why does the android Sarah not know that the real Sarah dislikes ginger pop and that she left her scarf with the Doctor? Are the dogs used to chase the Doctor and Sarah real dogs, and if so how did they get to Oseidon? If not, what are they for? If they are androids but are capable of following the tracks of the Doctor and Sarah, then why can't the other androids do the same? Waste of time making robot dogs, frankly. Why does the otherwise insanely detailed fake Devesham have stupid mistakes like the calendar with only one date in it? Why don't the androids in the pub grab Sarah in Episode One? If they're intelligent enough to realize that she could be part of some test, surely they're intelligent enough to bother to just hold on to her whilst they check with Styggron? Why, if most of the androids arrive at the pub in a truck before being properly activated, are some androids inside pods dotted around the village? Did they get bored and decided to play hide and seek? In Episode One, when Styggron tells Crayford that there might be rogue unit on the loose, does he catch a flicker of movement at the end of the corridor and immediately dive through a door to get at a gun? He can't possibly see that it is a stranger, and the androids are bulletproof. Well, probably: Styggron's claim that they are invincible is, as noted above, twaddle. To top it all off, the story ends with yet another notorious gaping hole as the Doctor uses a powerful electromagnetic field to jam the circuits of every android in the area, but then somehow manages to use his own android against Styggron. Apologists for this story might argue that this makes the Doctor look very clever, but given that he ahs only a few minutes in which to equip the android with a formidable array of shielding and reprogram it as well, I would argue that it makes Terry Nation look like a bit of an arse. 

Amongst all this rubbish, is there anything good about 'The Android Invasion'? Not really, no. The Kraals look quite good, but Styggron is basically a standard ranting megalomaniac with a mad plan, a line in gloating, and stupid dialogue ("Resistance is inadvisable!" Come back Professor Zaroff, all is forgiven…). Chedaki is voiced by Roy Skelton, who seems to have forgotten which of his roles he's in, as Chedaki sounds like bloody Zippy from Rainbow. Milton Johns is a fine actor, but Crayford is a ludicrous character; how on Earth he got the job of an astronaut if he's so paranoid that he assumes he's been deliberately abandoned when something goes wrong, and then agrees to help space Rhinos invade is a mystery, and then of course there is the notoriously stupid plot device of him never having looked under his eye-patch - does the man never wash?

The direction is adequate, the design uninspiring; the interiors of the Kraal base are forgettable and the spiky-bottomed doors just look daft. The whole set up in Episode One of the quite village with its inhabitants acting strangely is promisingly sinister, but delivers manure. Even the title is rubbish, suffering from the same basic weakness of 'Revenge of the Cybermen' in that its title undermines the mystery behind the first episode from the start. The regulars are fine; Tom Baker and Elizabeth Sladen are capable by this point in the series of playing their respective roles with consummate ease, and both tackle the feeble script well. John Levene and Ian Marter are also both their usual reliable selves, but they get little to do and it is therefore a shame that their last appearance in Doctor Who is in this story rather than the marvellous 'Terror of the Zygons'. Nicholas Courtney gets a particularly lucky escape in that respect, with the character of Colonel Faraday created as a stand in; Patrick Newell does well with what he's given, but the script paints him as a buffoon and the Brigadier had quite enough of that in 'The Three Doctors'. 

I'll end by pointing out one last plot hole; the Kraal fleet is poised to attack, but is never mentioned again after Styggron's death. In Episode Two, Chedaki tries to convince Styggron to abandon the androids, arguing that they are dangerous and that the Kraals can conquer Earth without them. Why then, do they not invade? The answer, and indeed the answer to all the plot holes in 'The Android Invasion' is actually quite simple: Chedaki and Styggron are lovers, but Chedaki is rather submissive; keen to please his completely loopy boyfriend, Chedaki humours his occasional plan to invade other planets even though they are ill thought out and obviously won't work. Once Styggron dies, Chedaki breathes a sigh of release and decides to quit whilst he's ahead, and/or goes home to Oseidon because he's too distraught to lead an invasion. Makes more sense than what we see on screen, anyway…