My Best Friend’s Exorcism by Grady Hendrix

Set in the 1980s, the story follows high school best friends Abby and Gretchen, whose lives take a dark turn after a night of experimenting with drugs leads to Gretchen's possession by a malevolent force. As Gretchen's behavior becomes increasingly erratic and sinister, Abby is determined to save her friend, navigating the challenges of adolescence, skepticism from adults, and the supernatural. The novel blends horror with humor and nostalgia, exploring themes of friendship, loyalty, and the struggle to overcome evil. Abby's unwavering dedication to Gretchen ultimately leads to a climactic battle against the demonic presence, testing the limits of their bond. The 8560th greatest book of all time