Detective Inspector Karen Eiken Hornby has returned to the main island, Heimö, after many years in London and has worked hard to become one of the few female police officers in Doggerland. So, when she wakes up in a hotel room next to her boss, Jounas Smeed, she knows she's made a big mistake. But things are about to get worse: later that day, Jounas's ex-wife is found brutally murdered. And Karen is the only one who can give him an alibi.

When 19-year-old Iselin Hanssen disappears during a run in a popular hiking area in Bodø, Northern Norway, suspicion quickly falls on her boyfriend. For investigator Jakob Weber, the case seems clear-cut, almost unexceptional, even though there is some suggestion that Iselin lived parts of her life beneath the radar of both family and friends. But events take a dramatic turn when another woman disappears in similar circumstances - this time on the island of Røst, hundreds of miles off the coast, in the wild ocean.

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.

Detective Leonore Asker seems to have the leading position at Malmö’s Major Crime Division within reach. But things go awry when, in the middle of a high profile kidnapping case, management relegates her to the so-called Department of Lost Souls—the unit for odd, cold cases banished to the basement of the police station.

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.