The main focus of the story is a young girl, Maša Artuković, allegedly possessed by Satan, whose deteriorating state results in the arrival of Viktor Supilo, a priest who is to conduct the rite of exorcism upon her. The ritual is to be performed in the presence of Maša's sister Vera, a known psychiatrist Sofija and an unannounced crew of TV reporters that want to expose exorcism as a controversial and dangerous ritual that has no place in the modern Catholic Church.

"Believe me. I know evil."