So even though the household has more or less bailed on giving a damn about watching Doctor Who, I have nonetheless been keeping an eye on the progression of the show via the recap posts that get posted to The Mary Sue and to Tor.com. (Notably, this recap post and this one.
Accordingly, I am now aware of the major spoiler that got dropped in part 1 of the season finale this past Saturday! Discussion of same behind the fold. And this IS a major spoiler, so DO NOT LOOK if you don’t want to be spoiled.