Simply salting and burning Karns' bones isn't enough to stop the haunting.

The Winchesters discover that they are dealing with the spirit of , a 19th-century preacher who murdered 13 people he deemed "immoral" using a silver hook.

In this episode, and Dean Winchester travel to a small college town in Ankeny, Iowa , to investigate a series of gruesome murders. The victims are being attacked by an invisible force, but witnesses describe a scratching sound—the chilling sign of a hook dragging across metal. Breaking Down the Lore