So meet River Song, but don’t blink. I have never understood the “she’s time traveling in one direction, he’s going in the other” bit, and I don’t think the writers do, either, but this is still a great episode. (River meets the Doctor for the first time in “Let’s Kill Hitler,” which is another amazing episode, but he’s Eleven then, so I don’t see how she recognizes him in this one since he’s Ten. Very confusing.) Also, that epilogue? Really, that’s what River Song wants to be, a stay-at-home mom to three kids? I have nothing against SAMs, Clara would be brilliant as a SAM, but ass-kicking, gun-blazing, “hello, sweetie” River? I chalk this up to Moffat not thinking things through.
But the story itself is an excellent example of how to build suspense, especially the use of you-can’t-see-it-so-you’ll-have-to-imagine-it monster, SO much better than showing the Silence or even the Daleks. Especially the Daleks. I love the Daleks, but they’re basically giant salt-shaker hovercrafts. The Vashta Nerada, though, they give me the cold grue.