Sam is intent on proving that he's still Sam on the episode "All Dogs Go to Heaven." In this clip, the brothers discuss their latest mission, which was given to them by Crowley.
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"I've done some shady stuff, but I am not doing this." What is Dean referring to with these words? Watch this preview for "All Dogs Go to Heaven" and get an idea.
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Supernatural Season 6 Episode 8 Quotes

Let me get dressed, Robo-Cop.

Dean

Is that Bobby Singer? Give him a kiss for me.

Crowley