One explosion takes place in the lab of the research institute of a chemical plant. Emil takes the blame. The director of the institute orders the work on the case to be suspended. After his jail sentence, Emil equips a lab in the dwelling he is renting. A little before the end of experiments there is another explosion. Emil is in the hospital. A friend announces him that the experiment was a success. Next to Emil is the girl he loves.

Before going on leave an experienced magistrate assigns to his assistant a case that has been all but concluded. Everything has been proved. The facts are clear: a brutal murder has been committed. The suspect is a young, beautiful girl, who does not deny or remorse the murder. The only thing that remains to be done is to refer the case to the public prosecutor's office. The case is rather strange though. The murdered man had been a criminal blackmailer; the murderess is a timid girl of 17. The young magistrate tries to discover certain vital truth concealed beneath the obvious facts. The girl has pleaded guilty and the bulk of evidence is against her. The only question that has not been answered concerns the motive of the crime. The detective carefully questions the girl to find her real motives. From her story he learns that the girl is real victim. She arrived from the country and due to her naivety ended up in the apartment of a sexual maniac.