I don't think any of the multi-Doctor specials ever tried to explain it, as such, but it's been a while since I've watched those particular serials, so I wouldn't swear to it…

Well, Time Crash was basically a comedy skit for the Children in Need charity special, with more than a bit of self-referential fourth-wall-breaking between Tennant and Davison, so its canonicity is somewhat questionable anyway. :)

Exactly why Missy is experiencing selective amnesia remains to be
seen—though the most obvious explanation is we’re dealing with the
out-of-sync timelines of multiple incarnations of the same Time Lord
encountering each other

"I say, what a wonderful butler, he's so violent."

Capaldi definitely feels like the most "classic" of the new-series Doctors to me. I'm not sure if he's deliberately channeling the earlier actors' nuances or not, but my impression of his performance is that there's quite a bit of Pertwee, Tom Baker, and even Hartnell in the mix — Capaldi's Doctor is tetchy,…

Well, to be fair, Donna wasn't intended to be a full-time companion when "Runaway Bride" aired, though. She was just supposed to be a one-off character for that episode alone; the next companion after Martha was going to be someone completely different. I imagine that if they'd known at the time that Donna was going…

Exactly! They were annoying because too many of their episodes wasted way too much time on their petty relationship squabbling instead of getting on with the "A" plot.

Frankly, I'd be perfectly content to have two or three more seasons of this kind of "normal." I, for one, have gotten a bit weary of season-long arcs of "companion as Impossible Mystery Girl who may or may not be the key to saving and/or destroying the universe."

Well, for better or worse, this episode did at least manage to hold my attention from beginning to end, which "Coach With The Dragon Tattoo" and "Nightvisiting" really didn't due to (IMO) poor and uneven pacing. (Not that "For Tonight We Might Die" didn't have its pacing problems as well, to be sure, but I'm usually…

I missed that bit as well — probably because that episode was so mediocre and poorly paced that my attention kept wandering at what were probably meant to be important moments like that.

Farscape would probably be a better example, then; the main cast was smaller, and at least two of the main characters were animatronic aliens operated by puppeteers from the Jim Henson Company, so the human actors had to do a lot more of the "running through corridors" work. (Not to mention that a couple of them had…

And yet, actors on American sci-fi shows like Babylon 5, Battlestar Galactica, the various Star Trek incarnations, or Farscape (okay, that last one's Australian / American, technically), somehow manage to not only survive more than three seasons' worth of shooting, but seasons in which there are twice as many episodes…

That's about where I'm coming down on it so far, too.