This episode is all about perspective.
You know, it might just be applicable that all of series four is about seeing the universe through someone else’s eyes. What starts off as a humorous plot device (splitting up Martha from the Doctor and Donna) becomes a much larger rumination on this greater idea: maybe, all along, the Doctor has really needed to see what he does through other people’s eyes.
So, of course, I was shocked at the concept of the Doctor having a daughter and I figured this would fill in some gaps of his past. It’s only technically his daughter, though, since she’s a clone, and I was initially disappointed at the concept. Oh, Stephen Greenhorn, I was so unprepared for where you were taking this story. Not only did I get some more information about the Doctor’s past, but the writers crafted the character of Jenny to be a much deeper reflection on the Doctor’s personality and history. And on top of that, there’s still one fantastically complex and exciting plot to tie it all together. Hell, this might just be one of my favorite Doctor Who episodes yet. – Mark Watches