When teenager Silas is found dead at a farmhouse on the Bjäre peninsula – the perpetually angry, odd but highly intelligent investigator Dani is teamed up with newly graduated police colleague Malik to investigate the case. The investigation leads Dani and Malik into a patriarchal rat-hole on the Scanian countryside and they soon find themselves at the center of a dark family feud that has been going on for generations. Dani, who has a personal connection to the victim Silas, is drawn deep into the investigation and the families it centers around. The Patriarch Elis gives Dani a deadline to solve the case before taking matters into his own hands within the family. Synden is a modern crime set in an uncertain world of conflict and violence where the original sin is constantly present.