Doctor Who 4x08 "Silence in the Library"

I didn't watch this last week, because I knew it was a two-parter, and from what people had been saying, it ended on a very cliffhangery cliffhanger. I was planning on watching both parts back to back, but time got away from me, so I guess I'll watch the next part tomorrow. In the meantime, my reactions to this one...
( here be spoilers )

Now off to read other people's reactions.