For the private detective Paula Schmidt in Stuttgart, things could be going better. In addition to her financial troubles, she also has to deal with her feelings for the attractive criminal investigator Brändle. That's where the elderly Hirschle from the third floor becomes a real nuisance. The senior citizen hasn't heard or seen anything from her neighbor, the private lecturer Martin Kirner, for weeks. Paula begins to investigate in Kirner's surroundings and is confronted with her own uncomfortable past in the process.