Frederike Bader, the former commissioner of the Berlin police, testified against a clan boss and now finds herself and her daughter in witness protection. With a nosy private detective on their tail, the past catches up to Frederike and Mia.

Private detective Zankl is arrested for the murder of his ex-girlfriend, Nunzia Rossi, and calls on Frederike to help him. In an effort to protect her daughter, Frederike agrees to investigate the murder.

Private detective Zankl recruits Frederike to help him on one of his assignments. The investigation brings them head to head with the Passau police department.

Adil Bahdari hires private detective Zankl to find his missing son, Ahmed. Adil doesn't know of the connection Zankl has to his son's disappearance. With the arrival of Adil Bahdari, Frederike and Mia are in danger once again.

Frederike's old boss, Jochen Mohn, stirs a hornet's nest when he wants his ex-wife's new partner investigated, so Frederike and Ferdinand are drawn into danger.

Texan Dave Henigan has come to Passau to trace his father's World War II history. Mia thinks his story has legs, but when she's followed and Dave disappears, Frederike and Ferdinand must investigate.