Someone is killing old spies. Retired and forgotten, these relics from the Cold War are being removed—quietly and brutally. And when “Section D” MI5 agent Tom Marlowe, on medical leave after a botched mission, learns his old mentor is one of the murdered ex-agents, he starts an investigation that threatens to cost him his career, his freedom…and even his life.

When Victoria Davies was pushed off her stately home's roof in 2001, all evidence pointed to her husband Michael. But now, 20 years later a letter has appeared, written by Victoria before her death; a letter that was never received, and a letter that brings new suspects into the fray; Labor MPs Shaun Donnal, Andrew MacIntyre, and Charles Baker.

There's a serial killer targeting the streets of Newcastle, seemingly picking his victims at random but subjecting them all to the same torturous end. When the Chief Inspector on the case goes missing, it falls on DCI Ryan to track down the man who is brutally murdering women and goading the police to 'catch me if you can'. As everyone becomes a suspect, Ryan and his team get drawn further and further into the case, but for Ryan the nightmare gets closer to home than he could ever have imagined.

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.

After an elite criminal profiling unit is shut down amid a storm of scandal and mismanagement, only one person emerges unscathed. Forensic psychiatrist Doctor Alexander Gregory has a reputation for being able to step inside the darkest minds to uncover whatever secrets lie hidden there, and soon enough he finds himself drawn into the murky world of murder investigation. In the beautiful hills of County Mayo, Ireland, a killer is on the loose. Panic has a stranglehold on its rural community, and the Garda are running out of time.

When a landslip on Pembrokeshire’s stunning coastal path reveals the harrowing remains of two bodies, ex-DCI Evan Warlow’s quiet retirement is shattered.

Northern Ireland, spring 1981. Hunger strikes, riots, power cuts, a homophobic serial killer with a penchant for opera, and a young woman’s suicide that may yet turn out to be murder: on the surface, the events are unconnected, but then things—and people—aren’t always what they seem. Detective Sergeant Duffy is the man tasked with trying to get to the bottom of it all. It’s no easy job—especially when it turns out that one of the victims was involved in the IRA but was last seen discussing business with someone from the loyalist Ulster Volunteer Force.

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.

Met cop DI Rob Marshall is hot on the trail of the serial killer known as the Chameleon, who has abducted, tortured and killed a series of young women in Northwest London. As they close in, the Chameleon—who switches identity to get close to his victims—shoots Marshall’s partner and escapes.

A master assassin craves one thing above all else: a normal everyday life. Trained to be a killer from the age of 11, Peter has never known the things the average person takes for granted. He has always been an asset. Burned by the CIA and now occupying their secret hit list, he works overseas as a Ronin, living a solitary life in hiding. But someone knows where he is. A strange man arrives at his door offering Peter the chance of a real life. "Get this done and you can be free," he is told.