When a boy leaps to his death from a bridge in the northern town of Umeå, Sweden, police discover drugs scattered in the snow near his body. The town has seen a dramatic increase in narcotic use among its youth, but nobody knows where the pills are coming from.

Haunted by his inability to track down and save his missing wife, DCI Robert Kett leaves the Metropolitan Police behind and moves to Norwich with his three young children, hoping to heal their broken family. But his newfound peace doesn’t last. Two newspaper delivery girls have gone missing in the city, and the clues point to a serial kidnapper. Kett is dragged into the centre of one of the darkest cases of his career - a case that pits him head-to-head against a horrifying evil.

When a body of a woman is discovered at a lighthouse in the Icelandic town of Akranes, it soon becomes clear that she’s no stranger to the area. Chief Investigating Officer Elma, who has returned to Akranes following a failed relationship, and her collegues Sævar and Hörður commence an uneasy investigation which uncovers a shocking secret in the dead woman’s past that continues to reverberate in the present day.

At a former sanatorium in the north of Iceland, now a hospital ward, an old nurse, Yrsa, is found murdered. Detective Hulda Hermannsdottir and her boss, Sverrir, are sent to investigate her death. There, they discover five suspects: the chief physician, two junior nurses, a young doctor, and the caretaker, who is arrested following false testimony from one of the nurses, but subsequently released. Less than a week after the murder, the chief physician, is also found dead, having apparently fallen from a balcony.

Icelandic sisters Áróra and Ísafold live in different countries and aren‘t on speaking terms, but when their mother loses contact with Ísafold, Áróra reluctantly returns to Iceland to find her sister. But she soon realises that her sister isn’t avoiding her...she has disappeared. As she confronts Ísafold’s abusive, drug-dealing boyfriend Björn, and begins to probe her sister’s reclusive neighbours, Áróra is led into an ever-darker web of intrigue and manipulation.

When a young woman is found lying half-naked in the snow, bleeding and unconscious, and a highly esteemed, elderly writer falls to his death in the local theater, Ari is dragged straight into the heart of a community where he can trust no one and secrets and lies are a way of life. Past plays tag with the present and the claustrophobic tension mounts as Ari is thrust ever deeper into his own darkness - blinded by snow and with a killer on the loose.

November, 1967, Iceland. Fourteen-year-old Marsi has a secret penpal – a boy who lives on the other side of the country – but she has been writing to him in her older sister's name. Now she is excited to meet him for the first time. But when the date arrives, Marsi is prevented from going, and during the night her sister Stína goes missing – her bloodstained anorak later found at the place where Marsibil and her penpal had agreed to meet. November, 1977. Stína's disappearance remains unsolved.

DI Jan Talantire is called to a cottage in Ilfracombe, where the female occupant is found dead, impaled with a crucifix. The woman, who had been renting the house for a few months, is well known locally, but the documents at the house indicate her real name is Ruth Lyle. The name means nothing to the young PC who found her, DI Talantire knows this cannot be the body of Ruth Lyle.

When a body is found on a lonely cliff top path, the angelic face of a murdered teenager lies facing the rising sun. Strangled by the hands of an unknown killer, it falls to DI Tom Janssen and his fledgling team to find out how she came to be there. Destined for a career in medicine, one to rival that of her parents, Holly Bettany’s future was as bright as it had been privileged. Seemingly, all that could threaten this promising teenager’s life was Holly herself.

On the day Stockholm police officer Hanna Ahlander’s personal and professional lives crash, she takes refuge at her sister’s lodge in the Swedish ski resort paradise of Åre. But it’s a brief comfort. The entire village is shaken by the sudden vanishing of a local teenage girl. Hanna can’t help but investigate, and while searching for the missing person, she lands a job with the local police department. There she joins forces with Detective Inspector Daniel Lindskog, who has been tasked with finding the girl. Their only lead: a scarf in the snow.

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.

My nine-year-old daughter Hollie should be leaving school smiling and laughing with all the other children but she’s not here. I run frantically, checking everywhere, my voice growing louder, but I can’t see her bright blue eyes and heart-shaped face anywhere. Pure panic washes over me. This is my worst nightmare. Her teacher asks me if she should call the police. My heart stops. I shake my head and pretend I’ve made a mistake. I see a look of suspicion creep into the teacher’s eyes. But the police can’t know. No one can. My hands shake as I realise I’m completely on my own.

In February 1986, the Halland police receive a call from a man who claims to have attacked his first victim. I’m going to do it again, he says before the line cuts off. By the time police officer Sven Jörgensson reaches the crime scene, the woman is taking her last breath. For Sven, this will prove a decisive moment. On the same night, Sweden plunges into a state of shock after the murder of the prime minister. Could there possibly be a connection?

Iceland, 1956. Fourteen-year-old Lára decides to spend the summer working for a couple on the small island of Videy, just off the coast of Reykjavík. In early August, the girl disappears without a trace. Time passes, and the mystery becomes Iceland‘s most infamous unsolved case. What happened to the young girl? Is she still alive? Did she leave the island, or did something happen to her there? Thirty years later, as the city of Reykjavík celebrates its 200th anniversary, journalist Valur Robertsson begins his own investigation into Lára's case.

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.