When a troubled novice is found garrotted in St Marguerite's cathedral, the first detectives called in are Bentz and Montoya. And Montoya knows who she is - Sister Camille was once his brother's girlfriend. He even knows the prime suspect: Father Frank O'Toole, rumoured to be the father of Camille's unborn child.
The deeper the investigation goes, the eerier it gets. More nuns are dying, brutally slaughtered by someone who seems to know their darkest secrets.
Bentz is sure Father O'Toole is their man. But arresting him is another matter. And there are other suspects, too, including a ruthless murderer who is supposed to have died years ago.
Has the monstrous killer known as Father John returned to New Orleans? Or is the truth even more twisted and terrifying?