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.

Southern Sweden: Beautiful countryside, endless forests, coastal walks, dark days - and even darker nights. But beneath the beauty lies a dark heart... Skåne, 1986: On the night of Walpurgis, the eve of May Day, where bonfires are lit to ward off evil spirits and preparations are made to celebrate the renewal of spring, a sixteen-year-old girl is ritualistically murdered in the woods beside a castle. Her stepbrother is convicted of the terrible deed and shortly after, the entire family vanishes without a trace.

Trying to process a life crisis Gothenburg policeman, Dennis Wilhelmson, decides to take a trip to his quiet childhood island, Smögen.

When Óttar Karlsson, a wealthy and respected government official and businessman, is found murdered, after failing to turn up at his own surprise birthday party, the police are at a loss. It isn't until young police officer Sigurdís finds a well-hidden safe in his impersonal luxury apartment that clues start emerging. As Óttar's shady business dealings become clear, a second unexpected line of enquiry emerges, when Sigurdís finds a US phone number in the safe, along with papers showing regular money transfers to an American account.

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.