7. A Town Called Mercy
A personal favorite of mine, 'A Town Called Mercy' manages to sum up the character of The Doctor in just 42 minutes. I find it so clever how writer Toby Whithouse took what could have been such a limiting premise it's set in the wild west (horrifying flashback to 'it's set on a pirate ship'...) but still, he makes so much of it. There are scares and sorrows abound in this mini-masterpiece that pits the Doctor against a big, mean cyborg and human nature itself. In 'Amy's Choice' the Doctor faces himself in a fairly literal sense, yet in this episode he is forced to confront his own sins in the form of another. Kahler-Jex embodies The Doctor in more subtle ways than The Master or The Dream Lord do but he no less resembles a side of the old man that he would far rather not face. Jex is a survivor of a war in which he lost his integrity and his honor for the greater good, just like the Doctor. He sets himself up in Mercy in order to atone for his sins just as the Doctor travels, righting wrongs in order to make up for his. The episode concludes with the gunslinger setting himself up as a guardian of Mercy to do the same and so we see in these three characters distorted mirror reflections of each other. It's a character study of a depth that one has no reason to expect from a family, Saturday-evening TV show. Ultimately this episode is about self-reflection and morality. How far will one go to the dark side before they cannot forgive them self and how can one forgive something in them self when they cannot forgive in another? So treat yourself, go and watch it again because this episode offers so much more than the average episode of Doctor Who.