Durham County

Newly promoted homicide detective Mike Sweeney struggles to keep his head above water. His family has been torn apart by serial killer Ray Prager, who's now in lockdown after murdering two women and traumatizing Mike's teenage daughter Sadie. Meanwhile, at work, Mike brings on forensic psychiatric Pen Verrity to help him understand the what seems to be a homicide involving the death of a baby.

Following the suicide of Elodie, Mike discovers her baby's death was accidental: the result of a bee sting. Mike tries to deal with his tragic mistake as Internal Affairs and a reporter scrutinize his actions.

Pen is relieved to find out that Audrey will be okay after the drug overdose that caused more harm than anticipated. Back at home, she discovers that Jonathan has told the newspapers that Bonnie's death may be a homicide and that Pen is a murderess. At the precinct, Mike loses his temper when Glenn tells him Ray's pals have served up an alibi and got him off one of the murder charges.

Jonathan's "assault" on Pen encourages Mike to push further the investigation. To determine whether Jonathan harmed Bonnie, Mike needs to exhume Bonnie's body - something Pen \ does not want to happen. Mike respects that and pursues other avenues of investigation, but his commitment to Pen is shaken when he discovers a fact that confirms Tom's hypothesis that Bonnie was poisoned.

Mike believes that Jonathan murdered Molly, putting him in conflict with Tom, who's convinced that Pen did it and set up Jonathan. Sadie, intent on facing her fears so she can stand up at the trial, reenacts what happened between her and Ray at the farm. She gets through it with Ray Jr.'s help, but the discovery of a braid of hair buried within the walls of the farmhouse devastates her.

Tom arrives at the farm, responding to Sadie's frantic call for help. She refuses to acknowledge her father as she tells Tom that Mike and Ray murdered Lissie here. Lissie's braid smells of smoke, a nearby tree shows signs of fire and a skull is buried beneath. At the station, she waits for Pen and wonders; will there ever be justice for Lissie's murder?.