Augh!!! I don't want to write about episodes 7, 8, and 9, but just want to skip ahead to all of the craziness that begins in episode 10 and doesn't end until the End of Time. But I have to. So I'm hereby clumping those episodes into this one post, to make it go faster. Not that it will be faster, but it's the illusion that counts.
Episode 7: The Unicorn and the Wasp.
Agatha Christie!!! I love her. The Doctor and Donna go back to the 1920's to see Agatha Christie, the day she mysteriously vanishes. There's a huge wasp, and it turns into a wonderful murder mystery, culminating in the stereotypical Agatha Christie fashion. Everyone gathers in the drawing room (or, occasionally, the parlor) and one by one they have some secret revealed, ending in the revealing of the murder. This was a style particularly favored by Poirot, actually. He's cool, too. Anyways, this was a fun episode. I loved how Donna kept making references to Christie's books which she hadn't written yet, and the Doctor had to keep going "Not yet." It was funny.
Episode 8: Silence in the Library.
This was interesting. There is something, in the shadows, eating people. If you have more than one shadow, you're about to get eaten. The Doctor teams up with some archaeologists, led by the mysterious River Song (with a TARDIS journal that I envy) to fight off the Vashta Nerada (which is a very Indian-sounding name), the creatures in the shadows at a huge library. One by one the whole crew gets picked off. There's also this strange other world that seems to be linked to the Library by a little girl who can control what happens in the Library. Donna disappears...
Episode 9: Forest of the Dead.
...and reappears in the other world. She gets married, pregnant, and has children in a matter of seconds. She's obviously being brainwashed by Dr. Moon. Meanwhile, back in the library, people are still dying. One of the more obnoxious archaeologists reveals that the alternate world is a save haven for his little sister (or some other relative), so she could stay alive, and have the library to keep her happy because she loved books. And she's saving people in the library from the Vashta Nerada by beaming them into her alternate world, which is what happened to Donna. Donna meanwhile meets one of the archaeologists, who explains what's going on, but Donna doesn't believe her (she finds it hard to believe that her children are non-existent) and so she doesn't get out until the Doctor and River Song beam everyone back. River Song does so by killing herself. The Doctor eventually manages to save her by using her imprint in the sonic screwdriver he apparently gives her in the future at some point. She knows a ton of stuff about him, and obviously knows a future Doctor, all of which information she records in her journal that looks like a TARDIS. The Doctor, despite being severely tempted (as anyone would be) doesn't open it and read it. Spoilers.