FBI Special Agent Faith Bold, hospitalized and haunted by her encounter with a serial killer, is ready to retire—when Turk, a K9 German shepherd, himself traumatized, comes into her life. When a new serial killer strikes, leaving his victims at the bottom of isolated wells, Faith, this time with Turk at her side, will stop at nothing to hunt him down and save the next victim before it is too late.

FBI Agent Jo Pullinger arrives in Seattle, Washington. She is grateful to leave behind her old life. One that involved having a transplant of a killer’s heart. When a wealthy family is murdered in their mansion, the daughter’s boyfriend is taken into custody. He was found at the scene of the crime, cradling the daughter’s body, with the murder weapon at his side. Jo’s instincts tell her the boyfriend is not guilty, even though, all the evidence is stacked against him.

Dylan First, a brilliant psychologist, is haunted by the horrific discovery of her past. Her mentor and father figure, a brilliant psychiatrist and professor, was secretly a serial killer. He is behind bars, but with everything Dylan thought she knew turned upside down, she feels lost when the FBI suddenly comes knocking. A new killer is using her mentor’s trademark signature. And they need Dylan to dissect his mind and stop him before it’s too late.

Thomas Austin was once a prominent NYPD detective, known for locking up a psychopathic serial killer dubbed "The Holiday Baby Butcher". Now retired in a small beach town in the Pacific Northwest, Austin runs a little café, trying to overcome the loss of his wife, a DA who was gunned down only one year ago.

After their last deployment, when she got shot, her fiancé, Martinez, got killed, and his bomb-sniffing dog, Elvis, got depressed, soldier Mercy Carr and Elvis were both sent home, her late lover’s last words ringing in her ears: “Take care of my partner.” On the Fourth of July weekend, when all of Northshire celebrates with fun and frolic and fireworks, the dog alerts to explosives and they find a squalling baby abandoned near a shallow grave filled with what appear to be human bones.