Okay, now that I have that out of my system, on to the review!
The TARDIS drops out heroes off on a planet where soldiers immediately force the Doctor to donate his DNA so they can make a cute, gun-happy blonde from it. The Doctor is displeased because guns are involved. And also that part about forced reproduction.
Donna names her Jenny, and wants to wrap her in a warm blanket, because seriously Georgia Moffett is as adorable as her real father. Martha, meanwhile, has been separated, and is helping the fish soldiers called the Hath. Both sides are fighting over the Source, which is called the breath of their Creator. They've been fighting for generations.
"I have this sudden craving for seafood..."
Cobb is displeased that the Doctor and Donna won't fight, and have convinced Jenny to do the same. He imprisons them all, but the guard is very, very lonely and the possibility of a kiss from Jenny is enough to make him go stupid.
As they try to make it to the Source before the two sides do, Donna notices dates written on different sections of the building, which gives them a time line of how this conflict got started.
It's been...oh, a few weeks. The two sides have been bred and killed off multiple generations in the space of a few weeks thanks to the progenation machine, which actually is horrifying.
Meanwhile, Martha has to watch her Hath friend die to keep her alive, and it's very sad because Hath are ugly cute in the same way the Ood are ugly cute.
They all meet at the Source, and the Doctor says they should just end the war because it's just a terraforming device, which will help basically everyone no matter what. This isn't enough for General Ripper, who tries to shoot him. Jenny takes a bullet for the Doctor, and it's very sad.
Martha has had more than enough of these shenanigans (which is ironic given what we find out later about her life). Donna wants MORE shenanigans, and decides to stay with the Doctor indefinitely, because it's better than living with Sylvia (which we can all agree with).
Also, spoiler, Jenny totally regenerates. We haven't seen her again, but she's been a bit busy.
Children to raise, 50th anniversary specials to direct, you know.
The Unicorn and the Wasp
Everyone loves Agatha Christie! The Doctor and Donna attend a party where everyone's favorite mystery author is in attendance.
Also, this is the day she will "mysteriously" disappear.
And, it wouldn't be an Agatha Christie reference without a murder mystery! When one of the guests is found dead, our heroes and author team up to discover the murderer!
Complete with incredulous and bewildered facial expressions.
Fortunately for Agatha, the Doctor has more experience with alien murders. Some substance left at the scene is morphic residue, indicating that the murderer is a shapeshifter. Now we have a bottle episode!
Meanwhile, Donna is attacked by a giant wasp. My nightmares usually involve giant spiders, but I'm not fond of the idea of a giant wasp either. The Doctor is then poisoned with cyanide, and we learn the very convoluted way Time Lord physiology handles poisoning. It involves tea, because this is England, dammit.
After Lady Eddison's son is stabbed to death, and her necklace is stolen. The necklace that was given to her by a Vespiform, a giant shapeshifting wasp. Who impregnated her.
Now that you've purged yourself into a trash can and presumably brushed your teeth, we discover that the reverend is in fact the child of that union, who discovered his shapeshifting abilities, and also decided that killing people like in Agatha Christie's books was a great idea.
Agatha lures him away with the necklace, and the wasp's death gives her amnesia. The Doctor uses the TARDIS to transport her ten days into the future, because the alternate solution is to realize that Agatha abandoned her child and hung out at a spa because her husband was going to leave her, and that just isn't good television.
Silence in the Library
WHAT'S THAT WE HAVEN'T HAD ANY NIGHTMARE FUEL IN A WHILE WELL WE BETTER GET RIGHT ON THAT.
A young girl is visited by a psychiatrist, the aptly named Doctor Moon. She can see this library in her incredibly vivid imagination. So vivid, she sees the Doctor and Donna burst in.
In fact, the pair have arrived at a 51st century library after a call on the psychic paper. The library is inexplicably abandoned, at least of humans. There are billions of non-human life forms that no one can see. An information node tells them to count their shadows, and name them one by one.
That one's Bob, and there's Janie Sue, and then we have Charlie...
An information node also informs them that other people are arriving, archaeologists led by the descendant of the library's builder, along with the Daves, the ditzy Miss Evangelista
AND THE MOST GLORIOUS HAIR IN THE HISTORY OF EVER.
I might have a slight problem.
The archaeologists want to know why the library sealed itself in 100 years before. But, in a more puzzling twist, River appears to know the Doctor, who has never met her before. She even has a diary decorated like a TARDIS! River sent the psychic paper message, and she says this is the youngest she has ever seen the Doctor. AND THUS THE MOST CONFUSING OF ARCS BEGAN. River, of course, refuses to explain herself at all.
Then we finally get some sort of sense out of all this. The library's operating system is somehow connected to the little girl's mind, and she sees what's happening on her TV. She may or may not be a Whovian stand-in, but let's not get too meta here. Doctor Moon tells her that the library is real, and that the world around her is a lie.
But Erica, you say, what about the Shadows?
No, not those Shadows. These shadows are the Vashta Nerada, living shadows that devour meat like a bunch of tiny, horrible piranha who love to give you more nightmares.
While River reveals she has the future version of the Doctor's sonic screwdriver and presumably knows his true name, Donna is the only person to be nice to Miss Evangelista.
Also, whatever happens to Donna, River is very very sad about it.
Then Proper Dave has two shadows, and he dies, and the Vashta Nerada chase them in the protective suit as the lights go out one by one.
The Doctor tries to use the library's teleporter to send Donna to the TARDIS, but instead of making it, her face appears on an information node, declaring that "Donna Noble has been saved".
Forest of the Dead
You remember the creepy little girl from the last episode? Well, she's still watching things along with us. Our intrepid heroes narrowly escape Proper Dave and the other possessed archaeologists. We soon discover what's happening: Lux's grandfather made the library for Lux's aunt, Charlotte Abigail Lux, who had an incurable disease and loved reading. The giant computer at the core houses "CAL"'s mind. The little girl tried to save everyone when the Vashta Nerada took over by uploading them to the computer core, just as she had done with Donna. But she's struggling to keep everything together, and not even the virus checker Doctor Moon is able to maintain control.
Speaking of, Donna is being treated by Doctor Moon in his mental facility. Wait, what? Yeah, all that, that was just in Donna's mind. Cross my heart, hope to die. Luckily, Donna's becoming more in tune with the real world, and Doctor Moon even finds her perfect man: gorgeous, adores her, and hardly ever speaks a word. But time is moving strangely for her, and next thing you know, she's got two incredibly creepy kids, and Miss Evangelista is there, glitching out and telling her that everything around her is fake. Unfortunately, this causes her not!children to disappear, and it's kind of horrifying.
It also produces a rather large amount of eye water...
Meanwhile, the Doctor is attempting to talk with the Vashta Nerada. They live in trees, which were used to make the books, and are now living in the books and devouring people, because there's not much else to eat in libraries. Worse, they decide the library is their library.
LIBRARIES ARE FOR EVERYONE, VASHTA NERADA. LIBRARIES ARE FOR EVERYONE
The Doctor comes to an agreement with them: give him a day to free everyone from the computer core. Unfortunately, this requires a Heroic Sacrifice, something the Doctor loves. He prepares to hook himself up to the computer terminal, but next thing you know, he wakes up handcuffed to a pillar, because that's how River rolls.
THIS IS WHERE THE TEARS BEGIN, PEOPLE.
River is already hooked up and ready to go. She reveals that while this is the first time he's seen, her, this is the last time she's seen him, meaning their entire relationship will be based on River's eventual death. She manages to fit in one last double entendre and one last "spoilers" before her death.
It's why her hair is so big. It's full of spoilers.
Everyone rematerializes in the library, where they are evacuated. Donna concludes that Lee was another figment made up by the computer, but she doesn't see him unsuccessfully trying to overcome his stutter before he himself is transported, Lo, even more tears.
The Doctor wonders why on Earth he would give River his sonic screwdriver, then finds a data recorder inside, meaning he can upload her to the computer. We leave River living in the computer simulation with her team members and the creepy not!children, while the Doctor realizes River is right: he can close the TARDIS by snapping his fingers!
And you guys, I don't care how much people hated River or her story, it is the greatest thing ever and I WILL GO FISTICUFFS WITH YOU ALL.
But seriously, I am amazed at how early Moffat was setting the stage for this story arc and how tightly it's plotted. Say what you will, I would have confused myself very quickly if I had tried the same thing. (Which is why I will never write anything with time travel.)