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.

Olivia is completely absorbed by the case and goes to Nordkoster to visit the murder scene. Stilton finds out through Situation Stockholm that Olivia is looking for him but is not interested in making contact. He has other concerns, like his homeless friends being beaten up.

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 Rönning is sure that Jackie Berglund is behind the attack and is trying to recover from it. At the same time Nils Wendt is found, who has been missing since 1987. Where has he been all these years and why has he shown up right now?

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.

Olivia is frustrated with the beach case, and decides to take revenge on the man who killed her cat. Stilton realises that the police are not going to spend any time on the investigation related to the murder of Vera Larsson and the beating of the homeless. He must take control of it himself.

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?