Unloved middle child

So Steven Moffat has delivered a three-parter by stealth, something he's apparently always wanted to do because it hasn't been done before (so did I imagine that that's exactly how they introduced the Derek Jacobi / John Simm Master at the end of Series 3?)

"The Pyramid at the End of the World" by Peter Harness and Steven Moffat, directed by Daniel Nettheim. Spoilers after the cut.

In fact I don't have much to say about this episode, which theoretically has a lot I should have liked but in practice didn't really do much for me. I think it's down to the pacing of trying to make a multi-part story that looks like standalones, and the middle one is going to suffer: It was trying to look like it was building to a resultion but it was obvious there was a cliffhanger coming, so it just seemed a bit off to me. Hopefully Toby Whithouse's alternate universe next week will wrap up this arc in a way that makes it worthwhile.