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 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.

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. 

When Grace’s husband, Adam, inherits an isolated North Yorkshire cottage, they leave the bustle of London behind to try a new life. A week later, Adam vanishes without a trace, leaving their baby daughter, Millie, in her stroller on the doorstep. The following year, Grace returns to the tiny village on the untamed heath. Everyone - the police, her parents, even her best friend and younger sister - is convinced that Adam left her. But Grace, unable to let go of her memories of their love and life together, cannot accept this explanation.

On a hot July morning on Sweden's idyllic vacation island of Sandhamn, a man takes his dog for a walk and makes a gruesome discovery: a body, tangled in fishing net, has washed ashore. Police detective Thomas Andreasson is the first to arrive on the scene. Before long, he has identified the deceased as Krister Berggren, a bachelor from the mainland who has been missing for months. All signs point to an accident - until another brutalized corpse is found at the local bed-and-breakfast.