The House of the Devil (2009)

A college student's babysitting gig goes spectacularly Satanically sideways in the slow-burn occultic horror flick The House of the Devil (2009). Samantha (Jocelin Donahue) is a college student in need of some extra cash. She answers an ad calling for a babysitter at an isolated farmhouse, but when she arrives she is told that there is no baby, just Mr. and Mrs. Ullman (Tom Noonan and Mary Woronov)'s elderly mother. The old woman is sleeping, they tell her, and all Samantha has to do is do homework and kill time until the Ullmans return. Could all this be a pretext to lure a pretty young woman into a Satanic ritual where she will be sacrificed to the Dark Lord during the dark of a lunar eclipse? Of course--there wouldn't be a movie otherwise-- and although Jocelin keeps her white nightgown on during the aforementioned ritual, we do get a titillating glimpse of her panties as she struggles.