In the eighteenth episode, chief inspector Boris Noethen receives a call from his old friend Claudia Benner. A young woman has turned up at her house who urgently needs help. She cannot and does not want to say more on the phone. Inspector Lucas is surprised when they stop with Boris in front of a mobile home on the outskirts of town, where Claudia Benner obviously works as a prostitute. They arrive too late: Claudia lies stabbed to death in her mobile home and they find no trace of the woman seeking help. Suddenly the BKA shows up at the crime scene and Boris has to clear the fronts. Kai Benner, Claudia's son, is surprisingly unemotional and seems to mourn the loss of income more than the death.
A first hot lead leads inspector Lucas and her team to Viktor Gheorghi, who was the last to be called by Claudia's cell phone and who had a car accident near the caravan just at the time of the crime. Although Gheorghi works as a security guard for a nearby brothel, he denies knowing Claudia and the stranger. Inspector Lucas stays close to Gheorghi and finds what he is looking for: During the accident, he was seen with Alina, most likely the woman who was last in Claudia's trailer. Inspector Lucas and her team are searching for Alina at full speed. After a raid on the brothel and a special operation by her assistant Tom Brauer, Lucas is certain: Eastern European women are being illegally forced into prostitution by a women's ring.
But what did Claudia Benner have to do with it, and where is Alina? Did they have contact with the illegal prostitutes? In the middle, the colleagues from the BKA show up again and hinder further investigations. Ellen Lucas knows that Viktor Gheorghi is the key to solving the case, but when he reveals himself to be an undercover agent for the BKA, she seems to be lost in the maelstrom of an inscrutable network of prostitution and human trafficking.