Isolated and under guard, the factory behind barbed wire and protective gates works to destroy deadly substances. But then the chemist Dr. Diestel (Kai Wiesinger) is kidnapped along with a vial of sarin gas—a poison that cannot be seen or smelt and kills its victims silently within minutes. Enough for an attack, sufficient for an act of terrorism. As quietly and unnoticed as the theft took place, so secretive must be the hunt for the perpetrator. "Don't raise panic and don't attract copycats" are the instructions from public prosecutor Anton Mehringer (Herbert Knaup). He commissions Sarah Kohr with the investigation—no fuss, but full authority. Sarah discovers that it's not a terrorist cell behind the crime, but rather someone with a very personal motive for revenge. She is able to secure the warfare agent, but the nightmare is far from over and escalates into an immensely threatening situation.