Good old Sheriff Mills (Kim Rhodes) calls up the Winchesters for their help on a missing persons' case that involves evidence of apparent superhuman strength and flashes of bright, blue light.
The brothers discover that not only were the missing souls all members of a local church, but also of its "chastity group".
After meeting church spokesperson Bonnie Fuschau (The Librarians' Lindy Booth), Sam and Dean decide to infiltrate the group.
Dean finds himself drawn to chastity counsellor Suzy Lee (Susie Abromeit), who he recognises but can't place from where. It turns out she has her own secrets that lead to Dean falling into the clutches of the story's antagonist.
Rock And A Hard Place is a fine, stand-alone story (except for some elements towards the end of the episode which reference of the overarching story of the season) that like last week's superb Bad Boys is very much a return to the traditional "monster-of-the-week" format that Supernatural is founded upon.
The episode has a nice balance between humour and horror, even though the central foe is perhaps slightly underdeveloped and could have done with more screen time to elaborate on its interesting motivations.
On the other hand, it's great to see Sheriff Mills again, a well-developed, but always growing, returning character who serves to add to the verisimilitude of the Supernatural universe by reminding us that people who survive contact with the Winchesters are invariably changed by the experience.