After five episodes Amy has finally been helpless. For me that is the highlight of the episode.
The episode is a great second part to the first story of the two part series, and it is also extremely important to the story arc. Moffat revisits a lot of the concerns that fans have been having about the stories thus far, in regards to what the crack is, it is an interesting take.
Back from last week though we get more of this future intrigue that I love so much. I love the Spaceship, this is something I miss a lot from the classic series. I love the forest as oxegen factory. I think that is ingenious.
River Song becomes even more mysterious with illusions to her killing the doctor, which is interesting. But, Moffat has once again found a way to undermine every thing else in previous seasons, and maybe even the classic series with one line "time can be rewritten" this has always been the consequence to the doctor that time could NOT be rewritten. If it could woldn't the doctor go back and save Adric or any number of others, couldn't he rewrite Donna's fate? Now that said I suppose it is because of this crack.
Back to the crack, I particularly liked the doctor calculating what it was in his head. This reminded me of Hartnel working a problem out in his head. IT is fascinating to watch and see what is going on in this story, as it is pivotal. . .
Now, lets talk about the end. Am finally tells the doctor she is getting married, and then precedes to jump on him because she "wants" him. For me she is another character in this scene almost as if she is trying to throw the doctor off the track, but of course this just helps the doctor figure something bigger out. And it is what I have been saying all along. Amy is the the story arc. . . I'm just not sure how it all fits in.