When five-year-old Ava Sawyer goes missing from a birthday party at a local garden center, the police are bewildered by the lack of leads. That is, until two years later, when Ava’s body is found and another little girl, Audrey Briggs, goes missing. Audrey also attended that party. Leading the investigation is Detective Natalie Ward. A mother of two teenagers, this case chills her to the bone and is a disturbing reminder of the last job she worked on. One that still keeps her awake at night.

A teacher goes missing under suspicious circumstances and a man is murdered at a local reservoir. For Detective Robyn Carter, there's no obvious link between the cases. But as she starts to delve into them, her investigations lead her to Abigail, perfect wife and mother to beautiful little Izzy. What was Abigail's connection to the victims? And why is she receiving threatening messages from an anonymous number?

Deborah Jenkins pulls her coat around her as she sets out on her short walk home in the pouring rain. But she never makes it home that night. And she is never seen again.

Four years later, an abandoned baby girl is found wrapped in dirty rags on a doorstep. An anonymous phone call urges the police to run a DNA test on the baby. But nobody is prepared for the results. The newborn belongs to Deborah. She’s still alive.

Ten years ago, the Harper family disappeared. Their deserted cottage was left with the water running, the television playing cartoons, the oven ready for baking. The doors were locked from the inside. Overnight, the sleepy village of Nighbrook became notorious as the scene of the unsolved mystery of the decade, an epicentre for ghoulish media speculation. For crime journalist Naomi, solving the case has turned into an obsession. So now, with Ivy Cottage finally listed for sale, it’s her chance to mount an investigation like no other.

DI Nikki Galena: A police detective with nothing left to lose, she's seen a girl die in her arms, and her daughter will never leave the hospital again. She's gotten tough on the criminals she believes did this to her. Too tough. And now she's been given one final warning: make it work with her new sergeant, DS Joseph Easter, or she's out.

When a woman's body is discovered in a cathedral and hours later a young man is found hanging from a tree outside his home, Detective Lottie Parker is called in to lead the investigation. Both bodies have the same distinctive tattoo clumsily inscribed on their legs. It's clear the pair are connected, but how? The trail leads Lottie to St Angela's, a former children's home, with a dark connection to her own family history. Suddenly the case just got personal.

Was the biggest case of his career the worst mistake he ever made? Ten years ago, DCI Jack Logan stopped the serial child-killer dubbed "Mister Whisper", earning himself a commendation, a drinking problem, and a broken marriage in the process...When another child disappears a hundred miles north in the Highlands, Jack is sent to lead the investigation and bring the boy home. But as similarities between the two cases grow, could it be that Jack caught the wrong man all those years ago?

When the body of a woman is found hanging from a tree in her front garden, rookie Detective Morgan Brookes is first on the scene. But Olivia Potter is past saving. And when her husband and daughters cannot be traced, Morgan knows there is more to this tragedy. And then she finds them. Lying huddled together in the dark basement, each of their faces covered with a small cotton cloth, their bodies cold to the touch. But as Morgan kneels beside the family, she realizes that one of the girls is still breathing.

In the remote forests of Stillwater, Minnesota, you can scream for days and no one will hear you. So when the bodies of two 15-year-old girls are discovered frozen in the snow, Special Agent Nikki Hunt is sure the killer is local: Someone knew where to hide the girls and thought they would never be found. Though Nikki hasn’t been home in 20 years, she knows she must take over the case.

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.

Meet DCI Lesley Clarke. She’s a straight-talking city copper who doesn’t suffer fools gladly…and she’s been transferred to rural Dorset. After being injured in a bomb attack, Lesley is presented with a choice - early retirement, or a period of respite in a calmer location. But things don’t stay calm for long. Before she’s even started her new job, Lesley is dragged into investigating a murder at one of England’s most iconic landmarks, the imposing Corfe Castle.

When the chief suspect in the notorious "peekaboo cop killer" case blew himself up, almost taking lead investigator DCI  Duncan Bone with him, the psychologically damaged detective thought his days on the force were over. But, when another PC is abducted and murdered in the same deranged peekaboo fashion, Bone is persuaded to return to lead the new investigation.

When two young girls disappear from their primary school, the village of Heighington is put on high alert - and not for the first time. Called in to investigate, Detective Karen Hart is sure that parallels with a previous disappearance are anything but coincidental. DS Hart is still reeling from a case she tried and failed to solve eighteen months ago, when a young woman vanished without a trace. She’s no nearer to the truth of what happened to Amy Fisher, but with two children missing now, too, the stakes have never been higher.

Former soldier. Ex-copper. Current man on the edge. Shunned by his old colleagues, and dividing his time between a dead-end job and the bottom of a whisky bottle, former Police Scotland detective superintendent Bob Hoon’s life is a mess. Then an old face from Hoon’s Special Forces days turns up asking for help: His teenage daughter has been missing for months, the police have drawn a blank, and he needs the kind of help that only Hoon can provide. And besides, Hoon owes him one.

Edinburgh is gripped by the greatest terror it has ever known. A lone bomber is targeting victims across the city, and no one is safe. DCI Ava Turner and DI Luc Callanach face death every day - and not just the deaths of the people being taken hostage by the killer. When it becomes clear that with every tip-off they are walking into a trap designed to kill them, too, Ava and Luc know that finding the truth could mean paying the ultimate price.