I know, I know, I know that everyone is posting little snippets of the Doctor's big speech from this episode and praising it and so on, but for me entertainment should not come with a lecture. If you have to beat me over the head with your message, you're not doing a good job with your writing to begin with. Add to that the fact your audience almost certainly has the same values as you—you're preaching to the choir—and it's a waste of time to even put such a message into the show.
Let me be clear. Everything the Doctor said is true, and it was well said. But I didn't tune in to be told I should believe something I already believe. Tell me a fucking story, and if that story has a point or a message that's fine, but don't knock me senseless with it, and don't bring everything to a screeching halt for it either.
Okay, but what about the episode itself (minus the lecture)? Uh . . . Clara sort of wakes up in the Matrix, I guess? Like, she's in a construct but her body is really in that Zygon pod. And she's communicating with Evil Clara, or Zygon Clara, or whatever you want to call her. She's able to throw off Evil Clara's aim just long enough to give the Doctor and Osgood time to parachute out of the doomed plane.
And then some other stuff, and the big lecture in which the Doctor insists everyone just get along, and everyone goes on their merry ways. Seriously. That's pretty much the sum total of this episode.
I have to question the efficacy of MIB'ing people's memories, though. If it's caused some 15 near wars, maybe it would be more helpful if the people could remember instead of getting this shiny new idea of starting another war? Maybe, "Oh, yeah, we tried that and it didn't work out," is worth something? I just don't see the point of lecturing someone, teaching them a lesson, and then wiping their memories of it.
Now, of course my understanding is the one Zygon that had been Evil Clara became the new Osgood #2. So I suppose she still has her memories. But what good does that do anyone really? She's not planning to travel the galaxy and preach this peace, is she? Will she at least shut down the Zygon terrorist training camp? Will the other Zygons listen to her if/when she tells them to stop? Or will they just pick a new leader? If this has happened some 15 times already, it means they keep picking new leaders, right? Is the Doctor just going to lecture them one by one every time it comes up? There has to be a better way is all I'm saying.