When the body of a successful architect is found in a quarry, the police assume it was an accident. Shortly thereafter, when his office falls victim to flames, a technical defect seems to be the cause. Early retiree Dieter Lukas and fellow retiree, police officer Ewald Müller, stumble upon the fact that something is amiss. Upon closer examination, shady individuals and connections emerge that the criminal police clearly fail to recognize. Müller and Lukas initially investigate on their own and cleverly guide the police onto the right track. To finally get the sluggish bureaucracy moving, Dieter Lukas has to come up with some clever ideas.