30-year-old Mathilda is on the verge of perfect adulthood with a job at a law firm and a stable relationship. But when her boyfriend proposes, an avalanche of emotions lead to questionable actions and put Mathilda's life in jeopardy.

A young gang member is found dead, and the Beck group's investigation indicates that a drug network is behind it. Klas Fredén has been monitoring the network for a long time, and the Beck group - led by Alex Beijer - is most graciously allowed to work with the murder investigation in parallel. She will soon end up on a collision course with Fredén. Thus, Martin Beck, who is now head of department, is also involved in the case.

A documentary about the Millennium Trilogy author Stieg Larsson and his pioneering work fighting right-wing extremists and neo-Nazis, an obsession with fatal consequences.

The series is named after a small part of Saltsjöbaden called Solsidan. It revolves around Alex and Anna who are expecting their first child and have just moved to Alex's childhood home in Saltsjöbaden, Stockholm County. Alex tries to get Anna to enjoy herself, and at the same time spend time with his childhood friend Fredde.