A UN employee working on crime prevention is killed under mysterious circumstances. The suspect is dead. Is it a normal death from a heart attack? Or a new crime? Agent Dronge, who leads the investigation, understands that the killer is one of the witnesses. But who? A modest narcotics expert? The head of the “regional department”? A high-ranking super-specialist? Motives for murder — however subtle, however nearly unnoticeable — exist for everyone. But the killer is only one. And the witness, who possesses important information, is being hunted…