Loved the episode. Was most upset to suddenly find it was a two parter. 
Same here. Loved the episode, another Steven Moffet "the stuff that you fear as a child is real" story.
I knew it was going to be a two parter (I had seen the list of episode titles and air dates), but what got me was that way that Space handled it.
They just cut from Amy shooting to commercial.
Then after commercial the credits were rolling. I thought I had missed something somewhere.
you thinking river?
If it is River you think that she would let on that she knows where this is going.
I know, I know, "Spoilers",
but that hasn't stopped her from letting something slip before, though that could be what the cryptic comment about "worse days to come" (iirc) to Amy is about.
The other thing, if it is River, how did she use the phone, the cord was cut.