Adapted from the 2016 novel by Grady Hendrix, “My Best Friend’s Exorcism” is a supernatural horror-comedy written by Jenna Lamia and directed by Damon Thomas. The film stars Elsie Fisher, Amiah Miller and Chris Lowell. It is currently available to stream on Amazon Prime Video.

Set in 1988, the narrative revolves around high school sophomores Abby Rivers and Gretchen Lang, played by Fisher and Miller respectively, two best friends who will soon be separated by Gretchen’s family moving away. During a weekend trip to a lake with friends, Gretchen is assaulted by an unknown force. As her best friend becomes increasingly cruel and erratic, Abby comes to believe that a demonic spirit possesses her and will stop at nothing to free Gretchen from its influence.

Though advertised as a horror-comedy, “My Best Friend’s Exorcism” can get surprisingly dark and melancholic when the viewer least expects it. The most disturbing horror is often what can draw parallels to real life experiences, and screenwriter Lamia expertly weaves unnerving realism into the supernatural elements. 

For example, Gretchen’s possession is at first assumed to be a sexual assault, and her behavior for the remaining runtime mirrors the trauma of such an event. Abby’s attempts to get help for her friend lead her ostracization from the rest of their school, and the pain of that isolation may prove even more frightening than the horror aspects for some viewers.

Director Thomas is adept at balancing the competing tones inherent to a horror-comedy, using character-based humor to give a brief respite from the gut-wrenching horror. Being a demonic possession film, the influence of the 1973 film “The Exorcist” can be felt, particularly during the thrilling climax. If there was one short-coming in Thomas’s direction, it would be the occasional use of unconvincing CGI that would have been far more effective with practical effects.

Complimenting this superb direction are the delightful performances of the main cast. Fisher and Miller have amazing chemistry, easily inspiring emotional investment in their characters’ friendship, and Chris Lowell is a refreshing take on the “exorcist” archetype.

“My Best Friend’s Exorcism” is a frightening, yet emotionally impactful tale of friendship and faith that is a welcome addition to the horror genre.