Well, I'm not quite sure that Toby Whithouse quite managed to make the second episode as good as the first, but I'm loving the new series of Doctor Who.
The Beethoven bit at the start was unnecessary: a rare example of the modern show not expecting the viewer to keep up, but assuming they’ll need an explanation – a pre-explanation in this case, but still. (Also breaking the fourth wall; most unusual.)
On the other hand, maybe some people would have been a bit lost at the end without it. Maybe all of us would have missed the point and weeks later we’d have gone “Wait, but he only did that because he –” Which has its own pleasure too, of course.
My main concern was that The Doctor let O’Donnell die, without any apparent remorse. I have a feeling that might come back to haunt him.
Also: loving the two-parters. Proper cliffhangers and all. How about a traditional four-parter next season?