Say what you will about the Master, but that guy’s arrogance always sets up his own defeat in the end.
Case in point, he’s the bad guy here and he sets up his own defeat due to his arrogance.
I think I am repeating myself…just like Castravalva!
Yes, Castravalva is collapsing on itself, the Doctor’s Zero Chamber is missing, and Adric is missing while the Doctor continues to recuperate from his latest regeneration. Eventually, Nyssa and Tegan find the Chamber. The women of Castravalva were using it in the town’s square to sort clothes.
The Doctor, meanwhile, finds some inconsistencies in the city’s official history. Like how it was a port city despite the fact it is clearly nowhere near a body of water. And when the local pharmacist shows up, the Doctor draws a map of Castravalva and asks him where his pharmacy is. To the man’s general confusion, it’s in four different locations despite the fact he only has one. A second man is similarly baffled as to why the Portreeve’s house is also in four different locations.
See, to these guys as natives, this only seems sorta wrong. To the Doctor, it’s Castravalva folding in on itself. So, the Doctor will just have to climb into the Zero Chamber to go see the Portreeve and see if the wise old man can be of any help.
He can’t, but that’s OK. The Doctor has a few things figured out. Like how the Portreeve was really the Master in disguise.
That was one of his better disguises, truth be told.
It’s also OK because while the Master taunts the Doctor inside the Zero Chamber, he doesn’t know the Doctor isn’t in there. Nyssa and Tegan know what’s up. The Doctor put the city’s history books in there, and he’s climbing up around. And now it all comes out. The Master’s tapestry hides a torture chamber holding Adric, and the city is a construct conjured from Adric’s mathematical powers.
Wait, math can do that? I’ll ask my friends in my school’s math department later.
Anyway, the Master is all set to destroy the Doctor, his companions, the citizens of Castravalva that he actually created, and Castravalva itself. See, he is a dick. Adric is being held in a web whose strands will instantly kill the Doctor if he touches one, but then the Castravalva librarian swings across on a chandalier and takes one for the team, dying to save Adric. And that makes the city’s collapse worse, but the Master being the Master hustles into a fireplace to escape because it was his TARDIS the whole time.
However, the Master being the Master, it also means he overestimated his own powers and his TARDIS is stuck inside with everyone else. The Doctor can’t find a way out. Even the natives used to looking at the place can’t find a way out. But Adric can! And he does, guiding everyone to an exit, but the Castravalvans, they’re kinda mad, and even though it dooms the lot of them, they restrain the Master and keep him from escaping.
I’d say that’s the end of the Master, but this is Doctor Who. It doesn’t matter that space/time just collapsed on top of him, theoretically causing him to cease to exist. He’ll be back as soon as a story requires him to be without the slightest bit of an explanation.
Anyway, the Doctor is all healed now, and the group even finds the TARDIS, tipped over after Tegan landed it but otherwise fine. And the Doctor? He’s feeling splendid.