Saarbrücken, deep in the night. An explosion shatters the silence. Sleepless Chief Inspector Pia Heinrich is the first on the scene: a security guard was killed in a brutal robbery of an armored car. When Chief Inspectors Leo Hölzer and Adam Schürk arrive, they are presented with a disturbing scene left behind by a massive explosion. What does the number sprayed on the street mean? Does a trail lead to an internationally wanted criminal gang in neighboring France? Chief Inspector Esther Baumann activates her contacts with the French police. Or does the surviving security guard know more than he admits? The team has barely begun their investigation when events take a dramatic turn and Pia is in danger...