Franziska does not believe that her brother died in an accident and investigates on her own

Franziska's brother, Gregor, was murdered because he knew too much about the dirty business of defective aircraft spare parts. After Georg's funeral, his wife Katrin is said to receive a high hush money if she signs that it was an accident. Franziska and Katrin continue the apparently hopeless fight against those who commissioned the murder.—ARD