FBI super-profiler Agent Meredeth Connelly begins her hunt for The .40 Caliber Killer. She collects evidence. He collects families. Her headaches become more unbearable with each crime scene, with each dead child. With two decades of experience, she knows serial killers. As the body count rises, it’s clear that this serial killer knows her. She doesn't remember him. He'll never forget her. As the investigation progresses, something awakens within her that hints at an answer.

Renowned criminal psychologist Bridget Bishop quit the FBI’s Behavioral Analysis Unit after only two years on the job, exhausted and traumatized from facilitating the investigation and capture of one of the country’s most prolific serial killers.

Twenty years ago Ed Finch – America’s most notorious serial killer – used the Bay Area as his hunting ground. Now, his daughter Margot is a homicide detective with the San Francisco Police Department who has spent her whole life trying to forget who she is. But her daddy won’t let her forget. When Margot receives a phone call from his lawyer, she learns that Ed is back – transferred to death row at San Quentin. And her father has a message for her: he’s willing to disclose some long-held secrets. But there’s a catch. She has to visit him.

When a world-renowned psychiatrist is found dead in an abandoned ranch house in the Californian Santa Carina Valley, a Post-it note with the words “Susan Parker” and a cell phone number is taped to the basement door. Still grieving her husband’s devastating suicide less than a year ago, FBI agent Susan Parker is taking a break from work and trying to rebuild her life as a single mom to her seven-year-old daughter, Natalie. When she’s called to the crime scene of Doctor Magnusson, a chill runs down her spine.

When Detective Billie Ann Wilde receives a desperate call that five-year-old Emma Wilson is missing, she rushes to the family home. But inside the picture-perfect house surrounded by Florida marshlands, she finds no children’s clothes or toys, no photos of the innocent child Emma’s mother Marissa describes. Billie suspects Marissa Wilson is hiding from someone.

Women are being found dead, contorted, and raped as the Pike Peaks Killer makes headlines. With Detective Frost's abilities doubted, and no new leads on the case, FBI Agent Jaxson Locke arrives uninvited to help with the investigation.

An eight-year-old girl, Chelsea Compton, is missing in Pine Valley, California, and for Detective Katie Scott it’s a cruel reminder of the friend who disappeared from summer camp 20 years ago. Unable to shake the memories, Katie vows she won’t rest until she discovers what happened to Chelsea. But as Katie starts to investigate, the case reveals itself to be much bigger and more shocking than she feared. Hidden deep in the forest she unearths a makeshift cemetery: a row of graves, each with a brightly colored teddy bear.

When Detective Maria Miller walks up creaking stairs into the attic of the old brownstone she senses this isn’t an ordinary crime scene. The brutality of the murder is enough to shock even an experienced detective like Maria. But there’s something else. An unsettling presence seems to lurk in the shadows sending a chill through Maria’s bones, making her desperate to run back down the stairs and never return. The killing is identical to the murder of an actress sixty years before, a crime that tore a family apart and sent shockwaves through New York City.

FBI Special Agent Emily Slate is no stranger to tragedy. After losing her husband three months ago, then botching the biggest case of her career, she’s barely escaped a full suspension. Determined to get her life back on track or die trying, she takes a seemingly impossible case in hopes she can turn her fortunes around.

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.