Forensic psychologist Kristen Bouchard is hired by the Catholic Church to determine whether a serial killer is possessed by a demon or merely a psychopath.

Kristen, David and Ben investigate a supposed miracle when a teenage girl comes back to life after being declared dead for almost three 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 the Catholic Church asks Kristen, David and Ben to assess the veracity of a local prophetess, Grace Ling, they are shaken when they see one of her visions come to life.

When Bridget confesses to murder during her exorcism, Monsignor Korecki asks Kristen, David and Ben to investigate if the details match any open cases and if the woman really is possessed by a demon.

When David recognizes one of the sigils in the Poveglia Codex from his father Leon's artwork, he and Kristen journey to a remote art commune to investigate its meaning and how it's related to David's family.

David is shocked to learn he is being sued for inflicting severe psychological harm on Caroline Hopkins, after he assisted in her exorcism. The accusation leads him to question his future as a priest, especially once he develops a very close connection with his defense attorney, Renée Harris.

Kristen, David and Ben are called to investigate an insidiously addictive Christmas song that's spreading among an increasing number of students, and the dangerous relationship between online influencers and their impressionable young followers.

After David is badly wounded, he is determined to fight off the menacing presence of death from his hospital bed.

Leland assists convicted serial killer Orson Leroux with having his conviction overturned; Kristen is called into court to testify while her daughter, Laura, undergoes emergency heart surgery; David witnesses a woman's evil instincts firsthand.

David, Kristen and Ben assess whether a pregnant woman is possessed when she claims one of the twins she’s carrying is evil. Their investigation leads to a fertility clinic where they discover a connection to all of their encounters throughout the season. Also, Kristen questions one of her daughters’ capacity for evil upon realizing that she also used that fertility clinic.

The team is given the task of evaluating the likelihood of Leland being possessed, which if decided true, would require them to exorcise him.

The team is charged with investigating a man who claims that he is hearing an angel.

The team encounters a nine-year-old girl, Mathilda, who is seemingly haunted by a Jinn, a spirit in the Islamic faith.

The team is sent to investigate the disappearance of a teenage boy, Wyatt.

Father Mulvehill asks the team for a confidential evaluation, as he fears that he might be the victim of diabolical oppression.

After the shooting of an unarmed woman, the team is tasked with investigating the police officer who pulled the trigger.

The team is dispatched to a monastery to investigate the corpse of Father Thomas, whose body has not decayed in the year following his death.

Kristen, David, and Ben are sent to Cornell University, at the request of Bishop Marx, to investigate an electrode-based experiment.

Bishop Marx tasks the team to investigate a UFO sighting, spotted by an air force pilot.

Ben, David, and Kristen investigate the RSM Fertility clinic - since so many of their past cases have led back to the ominous clinic.

The IRS taps the team to investigate the legitimacy of a new organization seeking religious status for tax exemption.

At Dr. Boggs' request, the team is introduced to a recently widowed Catholic named Nathan, and his teenage son, Elijah.

The team is sent to meet on campus with Mitch Otterbean, a student with a growing compulsion to eat human flesh.

David’s relationship with Kristen takes a turn when he gives into his temptation. Meanwhile, the team is tasked with exploring a machine to measure the weight of the human soul as it leaves a dying body.

Kristen, David, and Ben face the horrors of the internet as they investigate a Slender Man-style meme that scares teens into committing blasphemous acts in order to avoid death. Leland trains Sheryl in the fine art of online trolling.

Sister Andrea joins the team to fix a demonically possessed marriage, and Leland and Sheryl continue their crusade for Satan.

The team encounters a truck driver whose wife thinks he is possessed and explores the possibility of a demon haunting the highway.

Sister Andrea’s career and sanity are on trial as she battles Leland. Meanwhile the team investigates an alleged angel sighting.

A single mother enlists the team to look into the potentially demonic ways the viral app TipTop is terrorizing her family.

The team investigates a young man who is being held against his will to determine if he is possessed or is influenced by a cult.

The team responds to reports of possessed toys and electronics originating from a store. David is tasked with retrieving a hidden message that may be the key to saving the prophet Grace Ling.

The team investigates claims that a demon has been stalking people who have invested in a stock tip. The Entity asks for David's help in transitioning Grace Ling back.

The team investigates a household terrorized by a demonic infestation and is shocked when they find out the house is next door to Kristen's. Meanwhile, Kristen is surprised to learn that her frozen egg was never destroyed and purchased anonymously which leads her on a new adventure.

Kristen learns the details of Leland's evil scheme involving her ovum, and Sheryl's involvement in the plot increases the tension between mother and daughter. Meanwhile, David, Ben, and Kristen are sent to investigate a particle accelerator suspected to be a gateway to Hell.

Kristen, David, and Ben look into a possible werewolf attack that isn't what it seems. Andy grapples with his mysterious trauma, while Ben uses science to solve his Jinn problem.

Kristen's surrogacy faces complications, and the team visits a pig farm.

Andy is pushed to deadly measures as the team investigates a speech demon.

The team visits the Vatican as sinister forces besiege the Bouchard house.

Sheryl reaches her breaking point with Leland.

Ben begins to question his sanity, impacting his relationship with Renee.

Sheryl takes action to prevent a catastrophic event.

The team looks into bizarre text messages. Sheryl tries to beat Leland.

Kristen must protect her family. Sheryl and Leland's war peaks.

The team receives disappointing news. Kristen meets mysterious stranger Ellie, who claims to be an old friend of Sheryl's. A game between the two reveals disturbing information about Kristen's future...and about Ellie herself.

Sister Andrea gives the team their last assessment, a man who believes his doppelganger has possessed him and has a personal connection to the nun.

The Vatican asks the team to investigate a Hawking-like genius for potential ties to the occult. David's continued aiding of the Entity produces physical effects, and he and Sister Andrea say goodbye to St. Joseph's. Meanwhile, Leland returns home, where David confronts him.

An ominous countdown begins after the Bouchard girls start a new game on their VR goggles. The Entity moves to stop the Sixty, despite Sister Andrea's warnings. The team receives an offer they never expected. Kristen faces a final threat as Leland takes matters into his own hands.