This 1978 TV movie, Wes Craven's third horror, was based on a novel by Lois Duncan ("I Know What You Did Last Summer"). Although it's predictable, Linda Blair is a charm and the whole atmosphere quite cozy, making it worth watching.
Any horror movie starring Fran Drescher sounds petrifying to me, I don't care whether she stars as the supreme witch of a coven or simply appears in an insignificant supportive role. Growing up with a sister who insisted on watching that stupid show "The Nanny" over and over again, I've come to dread this unholy woman's quacking voice more than I dread all the serial killers in the entire world.