Alison's boyfriend Michael does some research on the building, and makes a startling discovery. The house is owned by the Catholic Church, and has an odd history. But who is Father Halliran? Is he trying to help Alison or harm her? And what about Michael? A cop keeps visiting Alison and telling her Michael may have been involved in the death of his wife. As the secrets of the building come to light, and the evil forces that are haunting her reveal themselves, Alison's true role in these events becomes clear. One thing is for certain; she has a very important part to play, and her life will never be the same. The Sentinel is perhaps not the best of the 1970s wave of satanic-themed horror tales, but it has some frightening & eerie moments. Directed by Michael Winner (best known for his work on several Charles Bronson films) the movie has what they used to call an "all star" cast, including Burgess Meredith, John Carradine, Ava Gardner, Eli Wallach, Beverly D'Angelo, Chris Sarandon and Cristina Raines as Alison. You can also spot Jerry Ohrbach, Christopher Walken & Jeff Goldblum in minor roles.
The movie is based on a novel by Jeffrey Konvitz, who also co-wrote the screenplay. If you're a fan of these types of films, it's worth a look. The location filming in New York City also adds to its overall effectiveness. I remember seeing it on late night TV back in the early 80s, and it definitely creeped me out. It's sort of a combination of the haunted house & demonic sub-genres of horror. The Sentinel would make perfect October/Halloween themed viewing. It's just been released on Blu-ray by Scream Factory with some extras: three different commentary tracks, including one by author Konvitz as well as one by star Raines, and another by director Winner. There's also a video interview with the film's assistant director, and some trailers & ad art galleries. Here's a link to the original trailer: https://www.youtube.com/watch?v=YMIssiMkt04.