A seven-year-old is found drowned in Fjällbacka, but it turns out that she has fresh water in her lungs. The girl is the daughter of one of Erica's friends.
When the crime writer Erica was 13 years old, her friend Peter got on a bus and was never seen again. Hidden secrets are revealed when Erica and her police husband Patrik begin to unravel the story. The mystery suddenly becomes greater when Peter's little brother is stabbed on his way to meet Erica. At a class reunion, tension escalates between those involved and another murder occurs among the childhood friends.
Crime writer Erica and her police husband Patrik solve murder mysteries when crimes from the past float to the surface in the idyllic fishing village of Fjällbacka. Erica's sister begins a flirtation with a presenter during a TV recording of "Antique in Cubic". A man is found murdered as Erica struggles to prove her sister's innocence, when she is accused of stealing a valuable painting.
On the same day that the Tanumshede police get a new employee, Hanna Kruse, they receive an alarm about a single-vehicle accident with a fatal outcome. The police initially believe that he was drunk driving because the deceased had a heavy amount of alcohol in his blood. But it turns out that the victim was already dead when she crashed. Someone has poisoned her. While the police are busy with the murder investigation, Patrik and Erica are planning their wedding.
One summer morning, a little boy sneaks out to play knight in Kungsklyftan in Fjällbacka. The game comes to an abrupt end when he sees a dead woman. Police are called to the scene and the mystery thickens when two women's skeletons are found underneath the murdered woman.