My Best Friend’s Exorcism (2016) is a young adult horror novel by Grady Hendrix. Set in 1980s Charleston, South Carolina, the novel explores the lifelong friendship between high school students Abby Rivers and Gretchen Lang. When Gretchen becomes possessed by a demon after a night of drinking and drug use, the girls’ friendship is put to the test.

This guide refers to the paperback edition published by Quirk Books in 2017.

Content Warning: My Best Friend’s Exorcism references and depicts violence such as physical abuse and sexual assault, mental health conditions such as suicidal ideation, self-harm, underage drinking, underage drug use, anti-gay bias, racism, enslavement, animal death, and potentially nauseating imagery such as the use of tapeworms for dieting.

Plot Summary

In 2008, 36-year-old Abby Rivers reads an article that Christian Lemon (Brother Lemon) has died. When Abby was in high school, Christian helped her exorcize a demon that was possessing her best friend, Gretchen Lang. Back in 1982, nine-year-old Abby is in fourth grade and planning an E.T.-themed birthday party at a skating rink. She invites her class, but a girl named Margaret Middleton plans a horse-riding party for the same day. On Abby’s birthday, only one child attends: Gretchen, who is new at school. At first, she rejects Gretchen, but then they bond over skating and music. Abby bumps into an older boy named Tommy Cox, who accidentally knocks her over, forcing her to get stitches. At school, Tommy gives her a can of Coke for her pain, which she saves for years. Abby and Gretchen remain friends, both attending the same religious private school.

In 10th grade, Abby and Gretchen are with Margaret and a girl named Glee Wannamaker on a boat near Margaret’s lake house, drinking. Margaret offers the other girls acid, which she stole from a stranger. To convince Gretchen to take the drugs, she claims she got them from her brother, Riley, who is a serial rapist and drug dealer. The girls take the acid and don’t feel different for several hours, and conclude it didn’t work or was fake. They decide to go skinny dipping, and Gretchen runs ahead of the others. Margaret warns her that the water is too shallow to jump in, but Gretchen keeps running. She doesn’t come out of the water, and the girls can’t find her in the woods or house. Abby finds an old outbuilding with Satanic graffiti. In the morning, she finds Gretchen near the building after seeing an eyeless figure who disappears. Gretchen can’t remember what happened, and Abby drives them home.

Gretchen starts experiencing visual and auditory hallucinations, and feeling invisible hands touching her. She has trouble sleeping, stops showering, and becomes reserved. She says she was attacked in the woods and thinks she’s having acid flashbacks. Gretchen starts acting angry and saying violent things. She also talks to a boy named Andy from Bible camp. Abby tells Gretchen’s parents that she was raped, but they tell Abby to leave and threaten her to not repeat her claim to anyone or they’ll have her arrested due to drug use and alleged distribution. The principal, Abby’s parents, and the chaplain Father Morgan also dismiss her concerns about rape and later, possession. Gretchen swerves Abby’s car into traffic and tries to remove her makeup (which she has always viewed as a means of security) at school. Abby refuses to accept Gretchen’s apology, and Gretchen becomes fully possessed by her demon (but appears outwardly normal); her soul is sent to a different location from which she can sometimes speak to Abby on the phone.

At a school assembly, a bizarre bodybuilder intuits that Gretchen is possessed. Abby meets with him at the mall food court, where he explains he’s not an exorcism expert but is determined to help Gretchen. Abby is uncertain, but has few options but to trust him. Gretchen gives Margaret weight-loss milkshakes that contain tapeworm eggs. Margaret drinks them and nearly dies, but is saved by doctors. Gretchen also forges love notes from Father Morgan to Glee, until she finally confronts him, then attempts suicide by trying to jump off a bell tower—but is saved by Father Morgan and maintenance people. Abby steals Gretchen’s notebook and discovers she was behind both attempted deaths. She calls Father Morgan for help, but Gretchen takes the notebook before Abby can show it to anyone. Gretchen also plants a stolen fetus from an anatomy lab in Abby’s house, leading police and Abby’s parents to believe she was the thief.

Deciding to perform an exorcism, Abby calls Christian, who drops her off at Gretchen’s house while her parents are out. Gretchen shoots her dog; then Abby drugs and kidnaps her, transporting her to her parents’ lake house for the exorcism. Christian forces the demon to reveal its name—Andras—but after several hours, gives up and leaves. Abby continues the exorcism using Christian’s notes, but doesn’t get far. She instead calls upon friendship, which works. Abby goes to court and is nearly sent to a facility, but Christian appears and claims the kidnapping was his idea, so Abby gets off with a restraining order. However, people harass her family, and her parents move them to another state. After a while, Gretchen visits Abby, and the two remain best friends.