The geriatric nurse Sabrina Dobisch witnesses a traffic accident and bravely tries to save the life of the young pedestrian Christian van Meeren. She then accuses the driver Doris Ackermann of premeditated murder. While Sabrina is celebrated as a courageous rescuer and enjoys public attention, Inspector Borowski remains skeptical: apart from the testimony, nothing indicates a capital crime until his colleague Sarah Brandt finds a gun in Doris Ackermann's glove compartment. Is there a connection between Christian van Meeren and Doris Ackermann? And what role does the piano teacher André Rosenthal play, who often spent time near the dead man?