A chief commissioner investigates the murder of a young woman and a fatal car accident. Apparently there is a connection between the two cases.

Katja's life collapses after the deaths of her husband and son in a bomb attack. After a time of mourning and injustice, Katja seeks revenge.

Lena returns to Germany after spending a year in Australia. Lena's mom and boyfriend are happy about she's home. Lena herself has mixed feelings. It is difficult to adapt to life in Germany again.

Follow the everyday work of a fictional police station on the Kiez of Hamburg.