Engel, die ihre Flügel verbrennen (1970)

Robert Susmeit, around fifteen or sixteen years old, watches his mother disappear into an apartment with one of her lovers. A student makes the apartment available for such purposes in exchange for a fee. When the lover goes swimming at the hotel, Robert beats him to death. The incident is witnessed by Moni Dingeldey, a girl about the same age who lives at the hotel with her mother. Her mother regularly picks up lovers at the bar and takes them upstairs. While the police search for the killer and Robert’s worried parents look for their son, the two teenagers pass the time together. The girl is precocious and cunning, with a slightly unhinged air, while the boy is somewhat awkward. Then Moni’s mother goes into the next room with a friend, and Moni, following the example she knows so well, kills the man in bed with a whisky bottle. Hunted by the hotel’s residents, the two leap from the roof, a sight the young detective can only watch helplessly, with tears in his eyes.