"At last, Doctor. At last I've cut you down to size."
IN THIS ONE... Nyssa finds out the Master killed her father, but the Doctor must ally with him after Logopolis is silenced and the universe starts to fall apart.
REVIEW: The serial has just gone bizarrely epic, as the Master finally appears in the flesh and proceeds to silence Logopolis' recited equations, causing entropy to flood the universe and unravel it. I'm not saying it makes sense (see Theories though), not when it seems to me the Logopolitans could just add in their heads, but the symbolism is potent. This Doctor is about to die, and the universe is falling apart around him. Even worse, perhaps, he must ally with the Master to set things right, leading up to a most distasteful handshake in the cliffhanger. It's a classic bit and used to happen all the time in the Pertwee/Delgado era, but this Master is on a real murder/doll-making spree I don't think Delgado ever approached. If the universe is created by the sentient mind, then it's thematically right that the sets should come crashing down when we're losing the most iconic of Doctors. It mirrors the start of the episode when he's trapped inside a collapsing TARDIS, crushed by the weight of its dimensions, as nightmare visions of his companions appear on the scanner. I don't particularly buy into all this entropy jazz (really? the universe is well past the point of entropy in 1981 and only Logopolis' calculations keep its structure stable?!), but it works in the context of this particular event in the show's history.
Introducing a new companion or two in the middle of all this might not have been the best idea, however. Adric is the nominal veteran, and his aptitude at maths is germane to the situation even if it isn't well used (he's just reading 2-character codes off a sheet in a sequence that makes it look like each Logopolitan is only in charge of one). Nyssa has a reason to be there, as she's looking for her father and falls victim to the Master, cruelly playing with her and forcing her to be HIS companion. But poor Tegan is being used as the generic Who girl, apparently knowing whatever the script needs her to know. Where to hold up a spreadsheet so the TARDIS scanner can read it, even though she doesn't know anything about the TARDIS, for example. She asks questions, but doesn't really question the reality of this whole situation. But then the script generally plays fast and loose with what people should know or not know.
On a personal note, I was disappointed to hear that Logopolis is responsible for the CVEs leading to E-Space, mathematical pinpricks designed to let some of the steam/entropy out of our universe and keep it stable. I'm disappointed, because I liked my theory about the Vampire King punching a hole in the fabric of space-time better. Well, since that happened a long time ago, maybe he still did, though that makes the whole revelation kind of ridiculous. I can't quite believe entropy had been achieved way back in the time of Rassilon. Seems I can never escape those dreaded Bidmeadisms.
THEORIES: That sentient thought can affect the very structure of reality in the Whoniverse has been shown time and again. The Logopolitans can create objects out of thin air through block transfer computation, while the Carrionites use words to achieve similar effects. Numbers and letters both seem to carry power. School Reunion had the villains looking for the God Code that would give them the same capacity. The TARDIS computer has a sentient element so it can configure reality within its own dimensional pocket. And I've discussed before how the Daleks might want to take Gallifrey because it is the key to "what the universe looks like". We "look Time Lord" because that planet is the template for most of the universe, its place in time giving it that heft, and the powerful minds on it casting some kind of mathematical shadow across history. If the Daleks take Gallifrey, we might "look Dalek" instead. The Mind Robber showed us a dimension where imagination became real, and more recently, Warriors' Gate had navigators who folded space-time with their minds. The mind is a very real force in the Whoniverse. Just had another thought... Maybe the reason the Doctor feels the need to destroy sentient computers so often isn't a case of Kirk envy, but rather to prevent a machine mind from achieving block transfer computation ability. Imagine a world created block by block at furious speed by the BOSS or Xoanon (come to think of it, that last one DID create its own world).
REWATCHABILITY: Medium - Thematically, it's really coming together, but there are still massive plot holes and too many companions for them to be well catered to.