Dean, Castiel and Mary have a lead on Sam and set out to rescue him. Dean is uncomfortable putting Mary in danger, but she insists on going. Meanwhile, Crowley is tipped off that Lucifer has taken over the body of rock ...
After a ballerina is found dead from dancing herself to death, Sam and Dean look into the case and discover the ballet slippers she wore were cursed. When Dean accidentally touches the shoes the power of the curse starts to take hold of him.
Sam and Dean discover that Frank's hard drive, containing everything on the leviathans, is now in Dick's company building. To retrieve it, they ask for help from one of the employees, a young computer hacker.
Dean returns from Purgatory, one year after the fight with the Leviathans. After reuniting with Sam, they find out that Kevin escaped Crowley with another Word of God that may hold the key to closing the gates of Hell forever.
Castiel decides to become a hunter, like Sam and Dean. But his first day on the job is a doozy when they investigate a series of murders caused by old cartoon gags. Meanwhile, Sam thinks back to his first time meeting Amelia's father.