Detective Sergeant Chris Waters got the call at 05.29 that July morning. This is it, said DCI Reeve, you'll be first there, it's all yours, you're the crime scene manager. Suddenly, after months of waiting and wondering, Waters finds himself in at the deep end, and alone at the scene of a puzzling murder. As the investigation proceeds, the detectives at Kings Lake Central find themselves visiting familiar places and talking to some familiar faces, while old enmities reappear in the incident room. Before this is over, Chris Waters will need to make a career-changing decision.

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.

D.I. Duncan McAdam is dispatched home to the Misty Isle. A body has been found buried in a remote location on the Waternish peninsula. Well-preserved in the peat, Isla Matheson—missing for the better part of two decades—is revealed to a shocked island community. A teenage runaway is dead...and no one is talking.

When a woman's body is discovered in a cathedral and hours later a young man is found hanging from a tree outside his home, Detective Lottie Parker is called in to lead the investigation. Both bodies have the same distinctive tattoo clumsily inscribed on their legs. It's clear the pair are connected, but how? The trail leads Lottie to St Angela's, a former children's home, with a dark connection to her own family history. Suddenly the case just got personal.