A man is found brutally murdered at a running track in the woods. At the same time, Josef resumes the relationship with a former girlfriend from school, Cissi, whose father recently died of a sudden heart attack during a robbery. Josef goes against Alex's directive and begins an unofficial investigation into Cissi's father's death, which puts him in a complicated conflict situation.

The young coast guard and diver Jessica finds two dead scuba divers after a storm. She disagrees with her superiors that it was an accident and seeks the help of her childhood friend Patrik. Patrik and Erica, who are on their way to a romantic holiday, make a detour to the beautiful village of Kungshamn. They soon become involved in the case. Erica hides her real identity as the policemans wife and is invited to join the museum association. Already during the first meeting she attends the associations chairman is found murdered... The three deaths are now officially opened for investigation, and the common denominator between the victims seems to have been an interest in the wreckage of a 1820s ship. Did somebody finally find it? And what cargo did it carry? What caused the ship to sink?

Lars interrupts his studies in mathematics at Uppsala University. Instead he takes a job as a teacher in an industrial community. When he discovers that one of his students is a mathematical genius, his desire for studies awakens.