A young pregnant woman is buried in the sand, slowly being submerged by the tide. 25 years later, the sadistic murder remains unsolved. Olivia Rönning at the Police Academy studies the case as a cold case exercise. Olivia becomes almost obsessed with the murder when she discovers that her father worked on the investigation. She quickly realises that she find the lead investigator, detective Tom Stilton, but he has gone to ground.
Stilton finds his friend Vera severely beaten and decides to try to find the perpetrators. Olivia has received information that a former escort girl, Jackie Berglund, figured in the inquiry on beach case and decides to examine her a little closer. Linn Magnuson, CEO of the mining company, receives a malicious call and realises that the call could crush both her and the company.
Olivia’s mother tries to tell Olivia to stop digging around in the beach case. She does not want to see Olivia become as obsessed as her father. Tom Stilton slowly begins to train himself so that he can pursue those who murdered Vera. He makes contact with his former snitch, Mink, for help in finding them.
Olivia contacts a child who was witness to the beach murder. From him she gets a hair slide with a few hairs on it. If there is DNA left on it, perhaps it could be the key to the murder mystery. The police finally breathe some life into Wendt’s mobile and see who he was last talking to. Linn Magnusson now realises that she must find the original recording of the conversation that could destroy her life.
Abbas has found Nils Wendt’s house in Costa Rica and his friend Bosques. Bosques says that the woman who was murdered on the beach on North Koster is Adelita Rivera and that she had a relationship with Nils. The murder at Nordkoster and the murder of Nils Wendt are now the same investigation. Olivia takes the help of Stilton’s former informant Mink.
Stilton is visited by his ex-wife in the caravan. She wants to see how he is and tell him that she has got a match on the DNA from the hair slide. Abbas is on his way home from Costa Rica and will go directly to the meeting with Mette, Stilton and Olivia. Linn wants to get hold of Wendt’s materials at any price.
Mette gathers everyone at the police station, including Stilton and Olivia. The pieces begin to fall into place, now they have identified the person who had the earring and are just waiting for a crucial DNA analysis. But how does the murder at Nordkoster fit together with the murder of Nils Wendt? And what is the motive?
Mette and her colleagues on the police now suspect that the assassination of Bengt Sahlman is linked to a batch of drugs stolen from the Customs Office. Sandra, who feels abandoned and unwanted, goes to her father's job to look for her computer. A visit that can have major consequences for the investigation. Something makes Mette mad at Oliva who takes care of Sandra. At the same time, Tom accompanies his friend Abbas to Marseille to help him find out what happened to Samira. This poses great risks when the city's largest criminal gang has prized Abbas's head.
Despite Mette's opposition, Oliva continues to search for Bengt Sahlman's death. She meets again the mysterious Alexander Popovic and their conversation arouses the interest in powerful forces in business. At the same time, the pursuit of the truth about Samira's death in Marseille continues. A stunt like Stilton is not quite comfortable with.
Abbas hovering between life and death and Michelle can no longer guarantee Stilton's safety. She forces him to leave Marseille, throwing him in a deep anxiety. Can Mette help him out of bed or is Stilton lost? New information makes Mette wonder about Stilton and Abbas travel to Marseille. At the same time, a new person enters into the investigation that makes the situation very difficult for Mette and not least Stilton.
Matte's heart does not work anymore and she ends up in hospital. This may be exactly what Rune Fors needs to remove her from the investigation, but Stilton does everything in its power to put an end to Fors. The engagement of the long-standing Klas Hall gives Mette colleagues an interesting track and at the same time Oliva raises the bet and goes undercover to access Borell.
Mette is now sick-wise, but still tries to keep up to date on the case, and despite her strict supervision, she is able to make plans with Tom. Abbas is determined to find Samira's killer, but as he stays in the hospital, time is running away and the French police have a head start. At the same time, Oliva tries to convince the Swedish police to look for Sandra's lost computer at Borell.