In 'Supernatural' episode 'When the Levee Breaks', Dean locks Sam up to detox him from being addicted to Demon's blood.
Next on "Supernatural", Dean and Bobby lock Sam in Bobby's panic room so he can detox from the demon's blood. Writer-producer Ben Edlund explained the addiction to E!, "The model of an addict bottoming out and becoming basically something else, almost a creature of reflex, is one of the things he's going to have to face. And that's going to make trouble for Dean and Sam-they don't agree on this particular issue. Dean's not happy about it."
However, as Bobby sees more seals are being broken he tells Dean they should let Sam out to help them fight the impending apocalypse. Dean disagrees and goes to Castiel for help. Sam and Dean have a big blowout confrontation.
Called "When the Levee Breaks", the episode airs May 7. Jared Padalecki who plays Sam mentioned in an interview with Pop Culture Zoo that this would be the most intense episode in the season that he has shot. "The first half, you'll know," he said shortly.