Oooooo! This is why Doctor Who stories should be spread over multiple episodes. So many of the Doctor Who episodes since the revival have been one-episode wonders where the story was rushed .. and a rushed story is often one not told as well. Even some of the two-parters since the revival have been too rushed. In any case these two stories are very well paced, extremely interesting, and excellent feats of story telling. That they were written by Stephen Moffett, the next lead writer, portends good things for the future of Doctor Who.
The story is about a library, not any old library but one that is the size of a whole planet and contains every book ever written. But, strangely, there is nobody there in this library. Why? The strange goings-on start almost immediately with an ominous message saying to watch out for the shadows. And shortly afterward a group of researchers burst upon the scene, one of whom, Dr. River Song, amazingly already knows the Doctor. Many creepy and odd events occur until there is another of the endings where someone sacrifices their life in order that the Doctor will live.
How many times is this now? Rose tried to sacrifice herself to save the Doctor, that lady in the Titanic story did do so, and now Dr. River Song. This thread of the Doctors story is touching into the unexplained Time War in which all the Time Lords were killed, eh?
The story contains a gaping enigma in the form of the villain, the Vashta Nerada (literally: the shadows that melt the flesh). They are explained as living shadows, shadows that act somewhat like piranhas in that they can instantly eat flesh off living creatures leaving just bones. They eat most of the crew by the end of the story with some amusing effects ("Hey, who turned out the lights").
But to me, with some little knowledge of Sanskrit, that name sounds like a Sanskrit phrase. I tried googling the phrase and all that turned up is other reviews of this episode. Fortunately the Wikipedia comes to the rescue to give the definition for Narada: Narada (Sanskrit: नारद, nārada) or Narada Muni is a divine sage from the Hindu tradition, who plays a prominent role in a number of the Puranic texts, especially in the Bhagavata Purana, and in the Ramayana. Narada is portrayed as a traveling monk with the ability to visit distant worlds or planets, lokas in Sanskrit. ..er.. A traveling monk who can visit distant worlds? The Namepedia suggests that Vashti is an Arabic or Persian name meaning 'Alive'. Together this doesn't say much, 'Alive+Traveling Monk' ...? Perhaps there isn't an obscure clue here at all. It's just an interesting bit of a detour.
Another gaping enigma is this new character, Dr. River Song. It's clear that sometime in the future she will be a companion for the Doctor and that in their future companionship Donna Noble is not present. Which leaves this question over what is going to happen to Donna? The Oood said something about her song ending soon, very enigmatic. And it's very possible that even though she says she's gonna stay with the Doctor forever, that she'll find as other Companions have found earlier, that she really wants to go home and settle down. In this episode for example she experienced married life with the home and kids and everything and ended up yearning so strongly for this guy she'd married.. so is this going to retrigger her Wife/Home/Kids dream and send her back to London in realizing that the Doctor simply will not ever in any way shape or form fulfill that dream for her? Or will something worse happen to Donna.
Back to Dr. River Song.. I read once about a Science Fiction publisher whose rejection form letter had a checkbox saying 'Heinlein did this better 20 years ago' and, as one of Heinlein's specialties was time travel weird out stories, this is the yardstick by which I measure other time travel weird out stories .. I believe this one, especially the Dr. Song character, to make the mark. She's a future companion, she knows she cannot tell too much ("spoilers") ..etc.. leaving so many enigma's especially as she's now dead other than a set of memories floating about the central computer.
The most interesting part of this enigma is the diary she carried around. A diary with a cover highly remniscient of the Tardis. She used the diary to try and gauge where this Doctor was in the timeline of her acquaintance with the Doctor. As if she'd met him multiple times and that the order of their meeting was out of order with his personal timeline. In each meeting it seems she had to know how much was safe to tell the Doctor she knew at that moment, because clearly "spoilers" would mess with the fabric of time.
And, the Doctors real name. I've been watching Doctor Who for a long time without realizing this core enigma of the whole show. What is the Doctors real name. He gets away without telling a name even though everybody else is saddled with having a name. I've been thinking that the Doctor may be someone who simply does not have a name .. but it seems now that not only does he have a name but that it's a very very very closely guarded secret. Hints have been dropped such as in the Shakespeare Code when the witch tried to find his name and couldn't, likewise in the Fires of Pompeii the Seer's tried to find his name and couldn't.
Dr. Song also has a couple enigmatic gizmos.. her own Sonic Screwdriver with capabilities beyond the Doctors (but, she says, given to her by the Doctor) as well as a 'squareness gun'. In the Dr. Who Confidential accompanying this episode, it's suggested that Dr. Song acquired Jack Harkness's squareness gun because it had been left behind in the Tardis.
Dr. Song also made some asides that are interesting. She went to the end of the Universe with the Doctor. She is someone who was able to "call" the Doctor and he would come. Someone else whom we've already seen has both of these attributes, Martha Jones. Martha went with the Doctor to the end of the universe (in Utopia) and Martha has a cell phone on which she can always call the Doctor (as in The Sontaran Strategem). Questions: Is Dr. Song a reshaped Martha Jones? That is, maybe Martha Jones went through a shape shifting episode to become Dr. Song? Or maybe the Doctor met Dr. Song and had a relationship with her very like the one with Martha Jones. In The Sound of Drums what did the Doctor whisper into Martha Jones ear? Did he whisper to her his name? The act of Dr. Song whispering into the Doctors ear was very much a mirror image of the Doctor whispering into Martha Jones ear.
Then there is a picture hanging on the wall in Charlotte's house picturing a blond young woman and a wolf.. er.. an allusion to Rose Tyler perhaps.