Tommaso is a successful, respected cardiac surgeon who also happens to be an atheist. However, Tommaso's son Andrea who is a medical student announces in a family get-together that he wants to become a priest. Tommaso is petrified with he hears the news as he expected his son was going to come out as homesexual. Tommaso who is irritated with Catholicismplan's with his son-in-law, Gianni to prevent Andrea's change.

Tommaso goes undercover while Andrea is absent, on retreat in a monastery, to investigate and bring down the charismatic Father Don Pietro, who he believes has "brain-washed" his son and caused upheaval in his family.