Great movies are ones that can be endlessly debated. Unfortunately, after watching “The Last Exorcism,” the only “endless” debates about this movie will be about the final five minutes that ruined an otherwise good suspense film.

Unfortunately, it seems as though he feels he needs all of his movies to end in the most horrific way possible and destroys a movie that has lots of potential but ends up as little more than a poor man’s version of “The Blair Witch Project.”

Presented in the form of a documentary, “The Last Exorcism” centers around Reverend Cotton Marcus (Patrick Fabian, “End Game”) as he undergoes his final assignment as a professional exorcist.

While the previous generations of men in his family performed many exorcisms, Cotton believes exorcisms are nothing more than an extreme type of therapy.

The first half finds Cotton showing his tricks of the trade on a young Nell Sweetzer (Ashley Bell, “Stay Cool”) whose father, Louis (Louis Herthum, “12 Rounds”), is convinced she is possessed after supposedly murdering numerous animals on their farm. Cotton does his job, collects his fee and begins traveling home. This is where the movie really shines.

Before Cotton leaves the city, Nell continues to act in ways that her father attributes to another demon possessing her.

Cotton doesn’t believe Louis at first but starts to question himself after witnessing several frightening acts that he believes no human could do.

While it certainly appears as though Nell is possessed, the film never strays too far into the world of the absurd. Each new development in the film is coupled with a plausible, scientific reason to explain Nell’s behavior, thus grounding the film in a very real-world context.

Nell’s actions are terrifying but not out of the realm of possibility. During the possession scenes, director Daniel Stamm (“A Necessary Death”) chooses to place the emphasis on the cries and shouts rather than on the visuals.

The problem with the movie is the ending.

While it first appears as though the audience must make up their minds as to what happened, a non-sensible reversal happens in the last five minutes that completely destroys the point of the movie.

Stamm decides to shove the answer down the audience’s throat rather than you deciding what really happened.

It’s insulting because throughout the movie, there are so many interpretations to every event. A good story will hint as the ending throughout the movie without hitting you over the head with the obviousness.

Not here. There is never any hint of the ending, and it only happens to tie up one minor loose end that was not important.

It was frustrating to watch this because with all of the potential this movie had to become a classic thriller in its own right, it will end up simply as another generic horror movie with limited ideas.