And The Way To Get It Right
1. Make The Reason That They Leave The Natural Conclusion Of Whatever That Character's Essential Story Is.
The clearest example of this is Amy Pond. The essential story of Amy Pond always boiled down to a choice - Rory or the Doctor. She was always going to have to choose between them. (Before anyone gets up in arms here, I'm not implying a romantic relationship between Amy and The Doctor, I'm saying that the choice was always going to be Friend or Spouse - Which life are you going to lead?) So, having spent two seasons (and a bit) establishing that she would, at some point, have to make that choice, we reach the end of The Angels take Manhattan and there it is, laid out dramatically in the clearest way possible. Go back in time after Rory, or go with The Doctor, Time to pick. So she finally chose between them, we got the dramatic payoff of having that question finally resolved, and Amy's story was fully told. Thanks, Girl Who Waited, it's been fun. This isn't limited to the new series, either. There have been a few good examples of this happening over the course of Doctor Who's 50 year run. For example, Ian and Barbara's storyline - reluctant travelers who only get the opportunity to return home after they've learned to enjoy their new life. Adric, the loser tag-along who never felt like he mattered, whose death ironically showed us that he did actually matter to his friends quite a bit. Kamelion- whose essential storyline was 'Can I overcome where I've come from and truly be good' and who found out that ultimately the answer was, 'No.' The Best example of this (and the best scene in the entire run of Doctor Who) is of course the departure of Martha Jones. Ironically - in light of a couple things I said about RTD a moment ago - this is also one of the most empowering scenes in the history of the show. Martha loved the Doctor. The Doctor did not love Martha. Martha respected herself enough to accept that and walk away. She didn't blame him. She accepted the friendship he felt for her for what it was, and she didn't lie to herself or him. 'I mean... He liked her. But that was it.' That moment right there was the most satisfying resolution that storyline could have had. That's the kind of resolution Rose and Donna were both cheated out of having. More like that please. I'm looking at you, Clara (Oswin) Oswald.