Forensic psychologist Kristen Bouchard is hired by the Catholic Church to work with David Acosta, a priest-in-training, and contractor Ben Shakir, to determine whether a serial killer is possessed by a demon or merely a psychopath. Kristen finds that she has a taste for the work and is invited to join the team on a permanent basis.

Kristen, David and Ben investigate a supposed miracle when a teenage girl comes back to life after being declared dead for almost two hours; Kristen meets with her former boss and runs into Leland Townsend.

After a high-strung theater producer's behavior turns from demanding to what is believed to be demonic, Kristen, David and Ben must assess the situation; Kristen discredits her nemesis, Leland Townsend, before he can ruin a 17-year-old boy's life.

Kristen, Ben and David are hired to evaluate Eric, a seemingly psychopathic 9-year-old boy; Eric takes a liking to David, which leaves them hopeful they can curb his violent behavior; Kristen's daughters lie about a game their grandmother bought.

On Halloween night, Kristen and David are sent to assess an exorcism; Ben goes on his favorite show, where he debunks supernatural finds with fellow unbeliever Vanessa.

When Kristen, David and Ben are asked to assess the veracity of a local prophetess, they are shaken when they see one of her visions come to life; David struggles with jealousy when he sees God speaking with the prophetess.