After a celebration in her rural hometown, Karla Petersen is murdered on her way home. Inspector Helen Dorn takes on the case but clashes with local officer Tom Petersen, Karla's brother, who defies warnings to find his sister's killer.

In an illegal arms case, three men, including two policemen, are dead. Mattheisen reveals a radical right-wing conspiracy, and suspects a mole. However, he is shot dead with Inspector Dorn’s weapon, while Dorn is found at the crime scene with no memory.

Haunted by a missing boy's case from 14 years ago, Helen Dorn recently discovers a lead linking to the alleged perpetrator, Ron Faber. Dorn immediately heads for Hamburg when she learns that Faber was apprehended with a deceased Chinese boy in his van.

At the Hamburg DOM festival, Helen Dorn and forensic scientist Weyer witness a paramedic's brutal assault. When a high-society boy is later found dead, unravelling a dark secret linking the two cases.

Haunted by a colleague's suicide and grappling with guilt, Helen Dorn confronts the unspoken accusations of her fellow officers. At the same time, she is assigned to solve a medical student's murder, where she soon uncovers their double life.

A fatal arson incident draws Helen Dorn into a far-left extremist community, who has targeted wealthy real estate agent Ralph Wagner. While they deny any involvement in the crime, it is indeed suspicious that they were previously almost ousted by Wagner.

During a hunting trip, Rolf Kanther, director of a military tech manufacturer, is shot right next to his daughter. Inspector Helen Dorn is sent to investigate the suspicious death, and needs to find out if it's an accident or a calculated murder.