Sam and Dean go to Missouri to track down a shapeshifter that kills its victi...
Supernatural: The Animation
Season 1 Episode 22: All Hell Breaks Loose: Part 2
In a surprise ending, Jake stabs Sam and kills him. Devastated by grief, Dean makes a deal with the crossroad demon to bring Sam back; as a trade-off, Dean gets one more year to live, after that -- his soul is toast.