"Changing history is a very fanatical idea, you know."
IN THIS ONE... Jo is sent to the future while the Doctor is held prisoner by time-traveling rebels. Until the Ogrons attack, that is. And first ever mention of the Blinovich Limitation Effect.
REVIEW: The episode starts the a botched reprise from the previous one, leading right up to the cliffhanger sting before someone thinks of fading it out. To make matters worse, the reprise has that awful, clipped Dalek dialog, which doesn't match the rest of the episode (voices are still not "dirty" enough, but at least they don't pause between each syllable), and that poor actress playing the computer masseuse gets to flub her line again. Bodes ill? In technical matters perhaps. For example, everything related to those laser guns is a bit of a hash. They don't emit beams, just sounds, so the big firefight at the end hangs limp, and when there IS a disintegration effect, it doesn't come with any kind of reaction from the actor. In a story where people routinely teleport (or time travel) in and out of scenes, it's rather confusing to have deaths look pretty much the same. And while we're on the subject of those guns, yes, the Doctor kills an Ogron with one, and it's not even made to look like self-defense (he's too far away for that). The third Doctor has been rather casual with life and death since at least Colony in Space and I don't know that I like it.
But this is a Doctor that's a bit uppity and superior, so perhaps there are life forms who are less important than others. I don't know that the production team is doing it on purpose (likely not), but this is a story in which Jo helps fascists (she doesn't know, but doesn't have an intuition either), and the Doctor is mistaken for an aristocrat and almost shot. Consciously or not, the story is building a comparison between the Doctor and the Daleks, and I'm guessing its lack of follow-through will be unsatisfying. Not that the oppressed (the rebels) are any nicer, of course, even if their leader is a rather attractive lady.
The Doctor spends most of his time bound and/or gagged, but the escape scenes are at least put to some use, usually explaining the plot to Jo. The Blinovich Limitation Effect is first mentioned, but not yet explained (the effect will change over time, so watch it turn into a misunderstood buzzterm by the JNT era). Essentially, it's what prevents you from interfering with your own timeline. They might have left it at that, but as you'll see, there are all sorts of consequences associated with this, which we'll have cause to discuss later. While the Doctor is tied up, the other regulars aren't much better off. Yates and Benton check out the house and that's it. Jo shares the Doctor's jeopardy before being whisked to the future (oops!) where she'll hopefully find something more to do than sell out the good guys to the fascist Controller (what's wrong with his complexion anyway?). And the Brigadier is stuck answering multiple phones at UNIT HQ. I have to say, Nicholas Courtney knows how to keep the energy up in these simple scenes and proves that a low-tech nerve center is a lot funnier than today's deals with all the big animated screens.
REWATCHABILITY: Medium - Usually, it's the third episode of a 4-parter that feels like padding when the script is thin. This time, it's the second, and it's way too early for that. Not bad, but our heroes need to become more proactive.