Well, that wasn't at all what I had been expecting. Click for spoilers
But what was good about it was that she was bred to be a soldier, and therefore had some of the Doctor's strengths, plus a few strategic strengths that he doesn't possess. Click for spoilers
The plot involved two warring factions who had been fighting for so long they had forgotten what the war was about. Martha ended up in the "enemy's" territory, so we got to see both sides. In this case, the humans seemed to be the real bad guys, though.
There were a few scenes that were a little bit lame, and sort of tried really hard to be emotional but just seemed to be trying too hard. Each time it was somebody crying over a person they had only met half an hour previously, which didn't really ring as true as they hoped.
But it had its good points, and though it's the worst episode of this season so far, it's still better than some of the really bad ones of past seasons, so that's a good thing.