In the middle 1800's. Peter Cushing is a priest who leads a group who go around looking for servants of the devil, mainly pretty young girls with dubious reputation. His two pretty young nieces arrive at the lcoal school, one of whom is drawn to Damien Thomas who is a vampire. The music teacher (David Warbeck) is trying to stop the vampires and expose the curelty of Peter Cushing but is also curiously drawn to the niece who has been turned into a vampire. This is one of the better Hammer horror films, with more than the ususal blood and sexual content, not least from the buxom Collinson twins.