Stretching a story about aliens invading Earth over eight episodes was a bit silly, even for a show as great as Doctor Who, simply because there was no possible way to keep the plot equally interesting throughout those eight chapters. I mean, even the writers of 24 are smart enough to let a storyline occupy four episodes at most, before moving to the next piece of the puzzle. Here, the slowness was particularly evident in the opening parts, as the actual Cybermen didn't appear until Ep. 4 and the real trouble began only in Ep. 7, meaning there was only one more show left to end The Invasion in a satisfying fashion. Fortunately, the epilogue is, for the most of it, really watchable.
Picking up from the previous chapter's cliffhanger, the episode opens with Vaughn at last fully convinced of the necessity to stop the Cybermen once and for all, leading to an unlikely cooperation with the Doctor. Meanwhile, UNIT's mission in Russia proceeds as planned. Here's hoping that the combined effort of the Time Lord and his human allies will be enough to save the planet.
Like Part 7, this finale benefits from letting Troughton do precisely what he wants: his Doctor is more energetic and lovable in this final installment than he has been for the rest of The Invasion, and the scenes he shares with the brilliant Kevin Stoney ring with real charm and suspense. Though in trouble, they are able to find whatever little humor there is and exploit it to perfection, adding a little relief to the danger. Unfortunately, Ep. 8 also follows its predecessor in not showing the evil robots at all, depriving the climax of a physically present villain that, albeit silent, would provide the situation with more adrenaline. I also found it hard to appreciate the country-side ending, which is just too relaxed to really fit in the apocalyptic nature of the rest of the story.
Not that bad a conclusion, but overall The Invasion isn't very special. If this really is Troughton's best adventure, as a magazine article suggested, I'm curious to see his worst.
7,5/10