Fire alarm again in Cologne! A series of arson attacks keeps the city in suspense, and now there are even fatalities. Three children die in the burned-out villa. Max Ballauf and Freddy Schenk need a quick manhunt because the intervals between the arson attacks are getting shorter and shorter. At the scene of the crime, the inspectors meet Karen Reinhardt, who is in shock. She has mild smoke inhalation but otherwise no injuries. She doesn't want to admit that her children didn't survive the fire. And there is no trace of her husband Gerald Reinhardt. Neighbors say he is employed by Cologne Airtech as an aeronautical engineer. But the investigation shows: He was fired here two years ago.