When Fiona Griffiths is tasked to look through a stackload of cold cases, her bosses don't expect her to find anything of interest. But then she finds that an impossible robbery really happened. That a nailed-on suicide was anything but. That the dead security guard was almost certainly murdered. Before long, Fiona is embroiled in what will become the toughest case of her career so far - one that forces her to enter the heart of darkness, and a journey that will test her mental toughness to its very limits.

At first, the murder scene appears sad, but not unusual: a young woman undone by drugs and prostitution, her six-year-old daughter dead alongside her. But then detectives find a strange piece of evidence in the squalid house: the platinum credit card of a very wealthy - and long dead - steel tycoon. What is a heroin-addicted hooker doing with the credit card of a well-known and powerful man who died months ago? This is the question that the most junior member of the investigative team, Detective Constable Fiona Griffiths, is assigned to answer.

Detective Sergeant Chris Waters got the call at 05.29 that July morning. This is it, said DCI Reeve, you'll be first there, it's all yours, you're the crime scene manager. Suddenly, after months of waiting and wondering, Waters finds himself in at the deep end, and alone at the scene of a puzzling murder. As the investigation proceeds, the detectives at Kings Lake Central find themselves visiting familiar places and talking to some familiar faces, while old enmities reappear in the incident room. Before this is over, Chris Waters will need to make a career-changing decision.

The story opens with the apparently accidental drowning of a sixth form student in the Norfolk countryside. As a matter of routine, or so it seems, the case passes across the desk of Detective Sergeant Smith, recently returned to work after an internal investigation into another case that has led to tensions between officers at Kings Lake police headquarters. As an ex-DCI, Smith could have retired by now, and it is clear that some of his superiors wish that he would do so.

Half-Scottish, half-Italian Enzo MacLeod used to be one of the top forensics experts in Scotland, and now he lives in Toulouse, working as a university professor. Divorced in Scotland and widowed in France, he has an estranged Scottish daughter and a French daughter he has raised by himself. As if his life isn't complicated enough, he soon finds himself unexpectedly on the hunt for solutions to some vexing cold cases thanks to an ill-advised wager about the power of forensic science.

Probationary constable Peter Grant dreams of being a detective in London's Metropolitan Police. Too bad his superior plans to assign him to the Case Progression Unit, where the biggest threat he'll face is a paper cut. But Peter's prospects change in the aftermath of a puzzling murder, when he gains exclusive information from an eyewitness who happens to be a ghost. Peter's ability to speak with the lingering dead brings him to the attention of Detective Chief Inspector Thomas Nightingale....

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.

Slough House is a dumping ground for British intelligence agents who've screwed up cases in any number of ways - by leaving a secret file on a train or blowing a surveillance. River Cartwright, one such "slow horse", is bitter about his failure and about his tedious assignment transcribing cell phone conversations. When a young man is abducted and his kidnappers threaten to broadcast his beheading live on the Internet, River sees an opportunity to redeem himself.

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.

Detective Chief Inspector Harry Grimm is forced to take leave from Bristol’s Major Investigations Team when his boss, tired of Harry chasing the ghost of his murderous father, sends him north on secondment. Used to city life and high stress, Harry fears his life will now be spent handing out speeding tickets, finding lost sheep, and directing tourists. But when a local teenager runs away, Harry finds himself pulled into an investigation much worse than anyone could have ever expected. 

DS George Cross can be rude, difficult and awkward with people. But his unfailing logic and dogged pursuit of the truth means his conviction rate is the best on the force. So when his police colleagues dismiss the death of a man as a squabble among Bristol's homeless community, Detective Sergeant George Cross is not convinced.

At 39, Manon Bradshaw is a devoted and respected member of the Cambridgeshire police force, and though she loves her job, what she longs for is a personal life. Single and distant from her family, she wants a husband and children of her own. One night, after yet another disastrous Internet date, she turns on her police radio to help herself fall asleep - and receives an alert that sends her to a puzzling crime scene.

When a police detective is taken off life support after falling into a coma, only an autopsy reveals the murderous act that precipitated her death. She'd been working on a special task force within North London's Nigerian community, and Acting Detective Superintendent Thomas Lynley is assigned to the case, which has far-reaching cultural associations that have nothing to do with life as he knows it. 

Retired publisher Susan Ryeland is living the good life. She is running a small hotel on a Greek island with her long-term boyfriend Andreas. And then the Trehearnes come to stay. The strange and mysterious story they tell, about an unfortunate murder that took place on the same day and in the same hotel in which their daughter was married - a picturesque inn on the Suffolk coast named Farlingaye Halle - fascinates Susan and piques her editor’s instincts. One of her former writers, the late Alan Conway, author of the fictional Magpie Murders, knew the murder victim....

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?