A Catholic father-of-four is arrested after a prostitute is found murdered, but he denies the crime.
An identical murder takes place while David Harvey is in custody.
After another prostitute is slain, Fitz comes to believe that David Harvey's wife Maggie is the killer, in spite of vehement protesting by the police and his brother, Father Michael.
Bill Nash smiles at Stuart Grady, and, in those few seconds, changes the course of their lives and inadvertently turns them both to murder.
Fitz is pitched against Grady and Nash, whose relationship is now spinning dangerously out of control.
Fitz privately advises a patient who seems to be having problems with her husband.
Fitz is asking DCI Wise to replace him with Irene as the killer may stop killing if she realises she is not getting the shrink's undivided attention.