Shortly before his son Jakob's wedding in Stuttgart, the former BKA target tracker and private detective Georg Dengler is asked for help by hacker activist Olga. Olga's friend Anne, an investigative journalist, sent her information on the darknet about secret blueprints for microwave weapons, lists of names of Bundeswehr officers and photos of tortured men. Shortly afterwards, she was shot by unknown assailants. At the same time, Anne's informant, Bundeswehr officer and Afghanistan veteran Florian Singer, is involved in a near-fatal accident in his car. Dengler and Olga get on the trail of the secret Fahrenheit program of the BND and Bundeswehr, led by Werner Kempf, and Katharina Petry's initiated research into microwave weapons at MeySis AG. Dengler and Olga stir up a hornet's nest of illegal weapons tests and international arms deals.