The Lüneburger Heide is burning brightly. At first everything looks like an unfortunate accidental fire, ignited by pure carelessness. During the extinguishing work, however, a charred body is found. This brings Commissioner Katharina von Hagemann and her colleagues to the scene - was it an accident or murder? The cruel answer is not long in coming, more fires in the vicinity follow, but the culprit is not a classic arsonist. The firebug is more: a serial killer who lets a person burn to death in every fire.