Season 2 Mission: Save Sam or Kill Him
* 2.01 In My Time Of Dying
(Sam helps Dad save Dean... unknowingly. 'Evil' can be a necessary spectrum of life.)
* 2.02 Everybody Loves a Clown
(Sam saves Dean. They start hunting demons. 'Evil' is interested only in self-preservation.)
* 2.03 Bloodlust
(Sam and Dean save 'evil' and stop 'good'. 'Evil' can be 'good' when acting on behalf of others.)
* 2.04 Children Shouldn't Play With Dead Things
(Sam and Dean save the unintended enemy by killing her, but not before she kills who she loved the most. 'Evil' can be created without the cooperation of the created. Acknowledging your fate is one thing; fighting it is another. She didn't fight it, she accepted it.)
* 2.05 Simon Said
(Sam and Dean are saved when someone with 'evil' powers kills his 'more evil' brother.)
* 2.06 No Exit
(Dean and Sam use bait to stop evil... echoing their Dad unknowingly. 'Evil' wanted to be caught.)
* 2.07 The Usual Suspects
(Sam helps save Dean. 'Good' kills her 'evil' lover who was stopping 'evil' with 'more evil'.)
* 2.08 Crossroad Blues
(Demons appear. Dean saves others, but 'evil' still escapes. Sam's danger is dubious.)
* 2.09 Croatoan
(Demons appear. Dean kills others, but 'evil' still escapes. Sam's danger is dubious.)
* 2.10 Hunted
(Sam saves Dean even though Sam was the one being hunted.)
* 2.11 Playthings
(Sam and Dean save others in a house where 'evil' is used to guard against 'more evil'. The 'more evil' was a lonely accident victim, the less 'evil' was hoodoo magic.)
* 2.12 Nightshifter
(Dean kills the 'evil'. Sam saves them from 'good'.)
* 2.13 Houses of the Holy
(The boys watch good people do bad things, or is it bad people doing good things?)
* 2.14 Born Under a Bad Sign
(Demons appear. Bobby saves Dean and Sam by identifying the threat. Bobby ends the immediate threat, but does not kill it. Can you be made to be 'evil', or can you just be temporarily manipulated into it?)
* 2.15 Tall Tales
(Bobby saves Dean and Sam by identifying the threat. Dean ends the immediate threat, but does not kill it. 'Evil' is exacting revenge for karmic trespasses: a being killing humans to balance the humans killing beings. He could have killed them, but he faked his own death instead.)
* 2.16 Roadkill
(Sam identifies and ends the immediate threat... by killing it. One of the rescued would have been considered 'evil' a year ago by virtue of her station, but Sam and Dean no longer identify her as a threat. She still has to die, but goes willingly.)
* 2.17 Heart
(Sam and Dean save others by identifying the threat. 'Evil' ends itself, becoming 'good' by going willingly to save others.)
* 2.18 Hollywood Babylon
(Sam and Dean save others by identifying the threat. 'Evil' is conjured against its will to exact revenge for karmic trespass and turns on its creator.)
* 2.19 Folsom Prison Blues
(Sam and Dean end the 'evil' threat by killing it. 'Evil' being a revenant who identifies and kills based on her own criteria of good and evil.)
* 2.20 What Is and What Should Never Be
(Sam saves Dean, then Dean saves Sam and others. 'Evil' trades life blood for a good story and what a story it could be... if you believe it long enough, it will kill you.)
* 2.21 All Hell Breaks Loose: Part One
('Evil' tells Sam a story about his destiny and puts him in a position where he can no longer reject it. Sam wants revenge while rejecting his destiny. Sam is betrayed by those he tries to save. Sam is forced to kill someone he did not identify as a threat or be killed in turn. Dean accepts the use of powers if it will save Sam... but it doesn't.)
* 2.22 All Hell Breaks Loose: Part Two
(Dean accepts the use of powers if it will save Sam...and it does. Sam wants revenge [death] and will accept his destiny to get it. Sam kills the one who had killed him. Dean wants Sam [life] and will accept a new destiny to get him. Dean kills the one who will kill him. 'Evil' is not what kills you, it's what makes you.)
Mission: Fail. The option of killing Sam is, of course, never considered an option but no one ever bothers to ask why John would recommend going all "Abraham and Isaac" on his own son. Sam is kidnapped and murdered. Dean sells his soul to bring him back.
WOW. Of all the episodes, I did not expect Hollywood Babylon, touted as a stand-alone puff piece, to show me the reason that the Yellow Eyed Demon wanted Sam and Dean all this time: revenge for karmic trespass, wherein the creator is killed by his creation before he sees his revenge fulfilled. It still comes to pass, though: they still open the gate...
the gate born upon the death of the youngest son and the foundation, the future, on the death of the oldest. But this revelation, this apocalypse, is only the beginning...
...