Treason as a plot device

I have yesterday watched Battlestar Galactica episodes “The Oath” and “The Blood on the Scales”. They were two best episodes since the very first “Miniseries” - the story of original Cylon attack on the Colonies. I realized that to a large extent this was due to the fact that it deals with insubordination and treason. But to make it even more moving you cannot help but feel sympathy or at least understanding to the traitors.
The Battlestar Galactica is a show with powerful, memorable characters. Each has an agenda, personal beliefs and some dirty secret. There is a lot of filler episodes that are not so interesting but help build the story arc and highlight some issues that will spring characters to action no matter the consequences. I think that there is something incredibly wicked in creating a plot where we see characters that we care about do something abominable because they firmly believe that this is the only way to save the day. And then watch as their hopes are crushed and they see how they were fooled by unscrupulous villains.
The treason or betrayal was always something the kept me turning the pages of the book or stare at the screen with an unmatched consequence. Especially, when traitor's think they do a good thing. I was so emotionally invested in the story of BSG as I was in Vernor Vinge's “A deepness in the sky” for the similar reasons. I couldn't stop myself waiting for a resolution of story – the day of reckoning. To watch the bravery and sacrifices of people that lost everything, but had a will to carry on and ensure that the justice will prevail.
I am now preparing to run “Burning Empires” RPG again and the nature of this game makes it so easy and so tempting to use similar themes. Who nows, perhaps even create such an incredible emotional tension.
If you have not seen “BSG” - these two episodes alone are worth to watch the whole thing. As great as the series is - I think these are unmatched. If you are for some more intellectual and even more gripping story – do yourself a service and read “A deepness in the sky”