Things should pick up from there but they never do. The scenes where we see the satanists doing their rituals are laughable. The head of the Coven looks like a reject from Olivia Newton John's infamous video for "Let's Get Physical." The only thing terrifying in these scenes is her sense of fashion. It made me giggle with glee.
Selleck gives his usual "man's man" performance and is oozing lots of early 70's testosterone. But even he cannot overcome a poor script. I give him credit for doing his best with very little to work with. The rest of the cast is tepid at best and mostly unforgettable.
When the "climatic" scene comes at the end of the film, I groaned. It goes out with a whimper and a horrible closing song. A total waste of 90 minutes to say the least. This is the kind of stuff that gives 70's films a bad reputation. Skip this one for sure.
For more info check out the film's entry in IMDB.