Käthe Hansen leads a quiet retired life in a small village near Oldenburg. Her routine is disrupted when the vagrant Strothmann stumbles into the village inn injured, claiming to have witnessed a murder – an employee of a fertilizer company in Oldenburg is dead. Unfortunately, the police suspect Strothmann to be the perpetrator. To clear him of this suspicion, Käthe and her neighbor Knut Sörensen take it upon themselves to investigate. Soon, the two of them need the support of the entire village.