What did you think of the Supernatural tenth season finale episode "Brother's Keeper" (10x23)? Dean tries one last time to go about his normal life, dealing with the Mark of Cain, but finds that he just can't do it anymore. So he summons Death (played by Julian Richings) and asks him for his help. Meanwhile, Sam urges Rowena (played by Ruth Connell) to remove the mark from Dean, not realizing that something devastatingly terrible will happen if the mark is destroyed.
Supernatural has been renewed for an 11th season (yes, you read that correctly - 11th) and will return in the fall.