Steven. Moffat.
You are a freaking genius.
AND I HATE YOU!! You and your damn cliffhangers!
Also, (for those of you who have just watched) answer me this. Why is the little girl a conduit to all the inner workings of the Library? Is she the universe's biggest hard-drive, camoflaged and hidden by someone who knows better (like her psychiatrist, Dr. Moon?) Is she the living Library -- the backup system for the millions of years of knowledge stored in those books?
Additionally, why does everyone's friendliest ER doc (aka, Professor River-Song) show up as an anthropologist, who has a TARDIS-shaped journal full of "spoilers" and a sonic SCREWDRIVER??? If she were simply a future companion, that link I could get. She knows the Future Doctor and she obviously knows the history of Donna (as her successor, maybe?) But, this woman has a SONIC DEVICE. And, as the Doctor himself says, he doesn't just give those out to anyone. Her sonic also looked, well, homemade. As if it had been constructed piecemeal rather than straight-from-the-factory. Why would the Doctor help her build -- or help her understand how to build -- a piece of Time Lordian technology if she's just a regular old human?
Plus (this sealed the deal for me) she is very familiar -- too familiar -- with the Doctor to be "just" another companion. She told Donna that having him look through her, without recognition, "killed her". Not hurt, not annoyed, but "killed". Not a word that's thrown around lightly. She also stroked his face. Stared into his eyes and said he "looked younger than she'd ever seen him". That observation seems fairly insignificant on the surface, yet to notice the imperceptible change of a person's eyes -- a change which runs deeper than the color, or the structure, but hinges on recognizing and understanding the emotions and age of the person behind the eyes -- means that she's been able to peer very closely at them -- at him -- before. Which could be very intimate, in any sense of the word.
Edit: I just realized that the Professor's sonic blaster might be the same make as Jack's was in TDD, Season 1. Both blasters are 51st century, presumably from the Villengard factory-turned-banana-grove. So, does this mean that Nine has not yet blown up that factory? Or, does it mean that the Professor has access to those types of weapons (through an organization like the Time Agency, or through her future association with the Doctor?)
Grr. I still hate Steven Moffat right now. Though he makes for brilliant two-part episodes, the man should not be allowed to write about mundane things. He makes them terrifying. Case in point, I am now more than a little suspicious of gas masks, statues of angels, and shadows.
P.S. In case you can't tell, when I start overanalyzing television into tiny bits (as in the above), that means I am officially an obsessed fan. Whee. :)