When Ryan Kennedy is imprisoned after killing a police officer, he knows what he has to do. Keep his mouth shut about who he was working for, keep his head down, and rely on his youth to keep his sentence short. When he gets out, he'll be looked after. Following the death in the line of duty of a fellow detective, DI Sarah Collins has left the capital for a quieter life in the countryside. But when a missing teenager turns up on her patch, she finds herself drawn into a much bigger investigation—one that leads her right back to London, back to the Met, and back to Ryan Kennedy.

DS Rakesh Siyal is an idealist. Frustrated as an Edinburgh human rights lawyer, he joins the police, determined to solve the problems he sees with the criminal justice system from the inside, rather than out. His first day as a cop sees him sent down to Galashiels in the Scottish Borders, where he’s given a simple task – return a suspect to Glasgow to face justice.

Detective Lauren Pengelly has only been part of the Penzance police force for less than two years, but that’s enough time to know that the sleepy Cornish town doesn’t see many murders. So, when the bones of a woman with a hole in her skull are discovered behind a derelict cottage, she immediately assumes the worst. Rallying her team, Lauren is flooded with a strange sense of relief when the bones turn out to be almost twenty years old, not a recent victim. But it quickly turns to dread when she receives her second heart-stopping call of the day–a little girl, Isla, has been kidnapped.

When Matt Ballard was starting out his career, three boys were murdered in the same area, the remote and bleak Gibbet Fen. When the main suspect was killed in a hit-and-run, the killings stopped. But Matt was not satisfied that the real murderer had been caught. Over 25 years later, Matt gets a photo in an unmarked envelope. It's of the Gibbet Fen crime scene. And the picture was taken before the murder took place. More photos arrive, relating to the historic murders, as well as intimate pictures of Matt's very secret private life.

Five years ago, DCI John Lomond led the search for notorious Glasgow child-killer ‘The Sandman', until personal tragedy forced him off the case. In Lomond's absence, the killer was never found. Now, with nothing but work left in his life, Lomond remains obsessed with the case–despite the nightmares it brings. When a child is abducted in similar Sandman fashion from an affluent Glasgow suburb, Lomond is brought in to find them before it's too late.

Starting a new life in Snowdonia was always DI Ruth Hunter's dream. Until a twisted killer turned it into her worst nightmare. Detective Inspector Ruth Hunter lives with the pain of her partner’s mysterious and unsolved disappearance. About to hit 50, the veteran police officer trades in the crime-ridden streets of London for a more peaceful life in rural North Wales. But Ruth has barely settled into her new position in North Wales Police, when the body of a brutally murdered woman is discovered...with strange symbols carved into her skin.

Meet Simon Fenchurch, detective inspector working the Met’s East London beat. Honest and funny but damaged, he’s working a case that could give him answers to his deepest trauma....

Detective Inspector Fenella Sallow is obsessive about her work and driven by her own demons. When the body of a retired artist is discovered atop the blackened embers of the town bonfire, the community is rocked to the core. It falls to DI Fenella Sallow and her team to find out how she came to be there. In her 50s, the veteran detective inspector thought she had seen it all. But behind the curtained windows and closed doors of the idyllic Cumbria coastal setting lurks pure evil.

After a scandal forces DI Kelly Porter out of the Met, she returns home to the Lake District. Crimes in the Cumbrian constabulary tend to be minor, but Kelly begins work on a cold case that shocked the local community - the abduction and brutal murder of a 10-year-old girl. 

A woman is found in a local cemetery, crushed to death under a gravestone. A production company is there, filming the remake of a classic sci-fi TV show on the grounds, making the investigation more difficult for DCI Harry McNeil. It's his first day in charge of the cold case unit in Edinburgh. After spending four years in Professional Standards, he has little choice but to take the promotion.