Roza Lanczeck, the girlfriend of company boss Frank Brenner, dies in a car accident. The evidence is clear: the car's brake seals were manipulated. So murder. When Lena Odenthal and Mario Kopper start their investigation, they only hear endearing things about Roza Lanczeck, even Katharina Brenner, the ex-wife of Roza's partner Frank Brenner, liked the young woman. Pregnant Roza and Frank wanted to get married and start a new life elsewhere. But the evidence speaks a different language: Frank Brenner only worked on Roza's car the day before the fatal car accident and Katharina is incriminating her ex-husband: Frank didn't want to marry at all, shied away from the responsibility for a child and wanted to get rid of Roza, she persistently puts it on record .
Frank Brenner, on the other hand, says nothing at all, mysteriously refusing to defend himself even after his arrest. The matter seems clear, but Lena cannot believe that Frank Brenner's love was only fake. She continues to investigate.