Watched the second episode of the current Doctor Who season, Day of the Moon, last night. Also rewatched the first episode, The Impossible Astronaut.
And I realized that I feel sorry for River Song. Each time, we encounter her (because we are following the story from the Doctor's timeline) it is earlier in her life. She is really a tragic character.
The first time, we encounter her, the Doctor does not know her. Obviously she has feelings for our beloved Time Lord. How heart-breaking that must be, to know everything about someone and not have them know (remember) you.
How terrible her interactions with the Doctor must be. Each additional time (from her viewpoint) she encounters him, he knows her less and she knows him more.
And how soon before the balance point is reached, and it is the Doctor who becomes the tragic character---knowing her more and she knowing less of him?
Quick commentary about Day of the Moon: There were some great lines. The first episode did not feel so choppy when watched back to back with the second. And there was the moment (if you saw the episode you know what I mean) that really drives home the point that River Song's is a tragic one.
If you have seen Day of the Moon, and want to see a chart of the Doctor's and River Song's timelines as they currently stand, check out this neat chart that someone made. (Sorry, I forgot the creator's name as news broke that Osama Bin Laden was officially dead.)