It’s hiking season in Black Rock Falls, and the small town in Montana is flooded with visitors. But when a hiker finds a human skull on a deserted trail in the woods that surround the town, Detective Jenna Alton is called in to investigate. With no missing persons reported, Jenna has no leads. Then her team makes a shocking discovery - the body of another hiker, a young man, tied to a tree and riddled with bullets. Could the two murders be linked? As more bodies are found, Jenna and her deputy David Kane know that they must venture deep into the forest to find and face the killer.

Hidden deep in the forest, schoolgirl Felicity Parker is found carefully laid out on a rock with nothing but a freshly picked bunch of flowers next to her lifeless form. Detective Jenna Alton is called in to investigate the gruesome discovery. With the body found just off a popular hiking route, Jenna believes the killer is a visitor to the town...until a second local girl is discovered.

Fifteen-year-old Lindy Rosen has been having nightmares for weeks, waking in a panic, screaming that there’s a man in her room watching her sleep. Her parents assumed it was her overactive imagination, but when one morning they find Lindy missing from her bedroom, they’re not so sure. Detective Jenna Alton is called in to investigate. Within hours of the schoolgirl going missing, the kidnapper reaches out to Jenna with a video of Lindy bound and tied to a chair, crying to be set free. And a simple message - you’ve got 24 hours to find her or I kill her. 

When a body is found stuffed into a barrel at a garbage dump, covered in long red lacerations, Detective Jenna Alton and her new deputy, David Kane, rush to the scene. Nothing ever happens in the small American town of Black Rock Falls, so Jenna believes the victim must be one of two recent missing persons, and she fears for the life of the other. Both were strangers to the town, but there's nothing else to link them. Jenna knows someone must have seen something, but no one's talking.

When Ella Tate stumbles into Black Rock Falls, her exhausted and bloodied body is a terrifying sight, but not as frightening as the story she has to tell. Ambushed on their way into town when they stopped to help a man by the side of the road, Ella and her friend Sky ran when he pulled a knife on them. But only one of them got away.

When seven-year-old Lucy Ross is snatched from the carousel in Denton city park, Detective Josie Quinn joins the frantic search. She’s the one who finds Lucy’s sparkly butterfly backpack abandoned by the ticket booth, a note with a devastating message stuffed inside: Answer your phone, or your sweet little darling will die.... The next day, Lucy’s parents are filled with hope when they pick up a call which they think is from their babysitter - but instead it’s a chilling male voice on the line.

When a park ranger stumbles across the bodies of Valerie and Tyler Yates by a creek in the small town of Denton, Detective Josie Quinn is first on the scene. Still reeling from the news that her abusive mother is dying, Josie suspects this is more than just accidental poisoning, and she’s right: Someone jammed a crudely carved pendant necklace down Valerie’s throat before she died. Combing the area, Josie’s team discover a third sleeping bag indicating there could have been an extra guest around the fire that night. A lucky escape? A missing victim? Or a suspect on the run?

Arriving with her partner Noah for dinner at his family’s immaculate countryside home, Detective Josie Quinn is devastated to find Noah’s mother, Colette, lying lifeless in the back garden, her mouth clogged with soil. Searching the house for answers, Josie’s team don’t know what to make of the rosary beads buried in the dirt near the body or the hidden file labelled “Drew Pratt”, the small town of Denton’s most famous missing person.

Watching her friend dragged away in handcuffs, Josie couldn't believe for one second that Gretchen had killed that poor boy. Confession or not, someone else was involved. She would find out who... When the body of a young student is found on the driveway of a local Denton home, a photograph pinned to his collar, Detective Josie Quinn is first on the scene. The house belongs to Gretchen Palmer, a dedicated member of Josie’s team, missing for the last 24 hours. Working around the clock, Josie is stopped in her tracks when Gretchen hands herself in to the police. 

When two young boys discover human bones buried beneath a tree in a trailer park, Detective Josie Quinn races to join her team at the scene. She used to play in those woods as a child, happier outside and away from her abusive mother, Belinda Rose. Josie’s past crashes into her present when a rare dental condition confirms the bones belong to a teenage foster-child who was murdered 30 years ago. A girl named Belinda Rose.

Everyone in the small town of Denton is searching for Isabelle Coleman, a missing 17-year-old girl. All they've found so far is her phone and another girl they didn't even know was missing. Mute and completely unresponsive to the world around her, it's clear this mysterious girl has been damaged beyond repair. All Detective Josie Quinn can get from her is a name: Ramona. Currently suspended from the force for misconduct, Josie takes matters into her own hands as the name leads her to evidence linking the two girls.

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 Natalie Ward is called to the home of 14-year-old Roxy Curtis she can’t help but empathise with Roxy’s distraught mother Cathy. Roxy hasn’t come home, last seen heading next door for a sleepover with her best friend Ellie. As the mother of two teenagers herself, Natalie knows that this is every parent’s worst nightmare. But when Roxy’s body is found in the basement of a beautiful Victorian mansion on the other side of town, Natalie’s darkest fears are confirmed. What was Roxy doing there? Cathy seems evasive, and Ellie refuses to talk.

One beautiful summer’s evening, thirteen-year-old twins Ivy and Erin Westmore snuggle down in a tent in their back garden, giggling and sharing secrets. When their mother goes to wake the girls the next morning, their tent is empty. The alarm is raised, and Detective Natalie Ward is put onto the case. When the twins’ bodies are discovered on nearby marshland, covered with deep pink petals, an icy shiver travels down Natalie’s spine. Everything about the girls’ deaths reminds her of a horrifying case she worked on earlier in her career.

When a cold, naked body is discovered by a couple on a jog through the lush woodlands of Pine Valley, California, new recruit Detective Katie Scott is stunned to discover the victim is Amanda Payton - a much-loved local nurse and the woman at the heart of an unsolved case she’s been investigating whilst getting a grip on her crippling PTSD. Weeks earlier, Amanda had run, battered and bruised, out into the headlights of a passing patrol car. She claimed to have just escaped a kidnapping, but with no strong evidence, the case went cold. The Pine Valley police made a fatal mistake....