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.
Skeptical female psychologist Kristen Bouchard joins David Acosta, who is training to be a Catholic priest, and a blue collar contractor as they investigate the church's backlog of unexplained mysteries, including supposed miracles, demonic possessions and other extraordinary occurrences. Their job is to assess if there's a logical explanation or if something truly supernatural is at work, examining the origins of evil along the dividing line between science and religion.