- Retroactive Brilliance after the events of Series 6 and 7: the Doctor was going to volunteer his brain as a conduit for the saved individuals' consciousnesses because it had such a massive capacity compared to everyone else's. We now know that River can do the same because she's a Time Lady(ish).
- Retroactive Brilliance: The contents of River's diary not only foreshadow towards the events Series 5 and Series 6, but also would've revealed Gallifrey's survival and the Doctor being granted a new cycle of regenerations.
- Doubles with Fridge Brilliance: River certainly recognized the Doctor, but didn't seem to recognize Donna and apparently didn't hear about the adventures that the Doctor had with Donna. But by the time River "properly" meets the Doctor, Donna was forced to forget about the adventures, and the Doctor was probably in no mood to discuss any more painful memories than he had to.
- She recognized Donna's name quick enough and looked very sad and reluctant to answer Donna's question about why River knew the Doctor but not her. She'd heard about Donna already, probably from either a later Ten, Eleven or Twelve. She just couldn't give her any more information as to why they'd never met.
- River knows she's going to die the entire episode. She doesn't let on because she knows the Doctor well enough that he'd try to stop her.
- Worse for 11. Every time he met her, every "I hate you"/"No you don't", he has already watched her die to save him.
- How does she know?
- At some point? She either is told, or figures out, that the first time the Doctor meets her, is the last time she meets him.
- This is implicitly confirmed in "The Husbands of River Song":
River: There are stories about us, you know. [...] Some of them... suggest that... the very last night we spend together is at the Singing Towers of Darillium. That wouldn't... be true, would it?
The Doctor: ...Spoilers.
- 4022 people were taken out of existence for over a hundred years. When they are brought back into existence, they'll all find that the world has been moving on for over a century. Either their loved ones will have died of old age, are approaching said point in their lives, or they'll have long enough lifespans to still be alive, but have moved on with their lives long since.
Fridge Logic / Headscratchers
- The Library seems to have been horribly under-utilized. The size of a planet, and only 4022 people on it? Worse yet, the computer had to invent two children — not one single child was on the planet, reading any of the special editions of Dr. Seuss or Judy Blume or Danny Dunn?
- It's not the only library in the universe, and it's certainly not the most convenient as long as there is one on your own planet. People went there because of specific books they need or because they are book lovers or tourists that wanted to see the biggest library because it's the biggest library.
- It could have been that the shadows struck during a particularly slow day or time period for the library. For that matter, the planet may not necessarily be Earth-sized either, so it could only hold so many people to begin with.
- If the Library was completely infested with Vashta Nerada, why couldn't CAL have teleported the people to the Dr. Moon when the creatures initially hatched? If the moon was an artificial construct for virus-checking, you'd think it would need its own computer-core, with sufficient life-sustaining facilities for the workers who'd built and programmed it in the first place. Teleportation can operate up to a light-year's distance in this Verse, so a moon certainly wouldn't be out of range. There weren't any books on the moon either, so there'd be no spores to hatch: the Library patrons could've waited for rescue there in safety.
- Possibly that's what she'd intended to do when she "saved" them, but the sheer number of patterns being transferred at once overloaded the teleportation system, leaving her no choice but to store the lot of them.
- The moon doesn't necessarily have a large enough space, or great enough life support capacity, to hold several thousand people. It could be that all the space inside is taken up by the computer itself, plus cooling systems etc, with only small accessways which are not pressurized unless someone is working on the moon at that time. Even if she could provide enough space and atmosphere, it would likely take too long to bring up the temperature and atmosphere to habitable levels. She could have meant to store them only until the moon could be made ready, but the sheer amount of data overwhelmed the system, and she couldn't finish the job.
- Maybe this planet's teleports are only equipped to work from one teleport station to another around the planet and no further (or they usually can teleport to the moon and back, but can't send that much data).
