Three prostitutes are found murdered in Antwerp, Berlin and Copenhagen. They were all killed in the exact same way, and all within hours after having been visited by a Belgian journalist.

Lithuanian billionaire Marius Loukauskis is associated with the investigation. Loukauskis suspected of leading a large criminal network operating in human trafficking and forced labor. He has a top spot on Europol's list but has so far been untouchable. The famous jazz singer Iris Gabler promising a reward for information that could lead to the arrest of Maria's killer. Maria was her daughter.

The prostitutes that were interviewed by journalist Jean-Louis Poquelin, turn out to have been testifiers against Loukauskis. Poquelin wanted their help for an upcoming book.

Bruno Koopmann, Loukauskis's head of security, murders local pimp Theo Janke. Loukauskis knows the police have found themselves yet another reason to keep an eye on him.

On her way to another witness, German police chief Jackie Mueller gets shot and severely injured. Danish chief Harald Bjorn and Belgian chief Alicia Verbeeck come over to Berlin to track down the culprit.

The Danish police are on their way to an illegal chicken farm. When they arrive, they find the building to be ablaze. A lot of the slave workers as well as evidence go up in flames.

Loukauskis is able to escape the police. They immediately set up an international warrant for his arrest. Within their process, they discover Loukauskis has once raped a 14-year-old girl.

The police team is finally able to uncover the slavery network and its shocking efficiency. Loukauskis meanwhile goes into hiding in the Belgian countryside.

Seven people are murdered in a brutal shooting in a bed and breakfast in Denmark. The only survivor of the massacre is the young Syrian woman Malu Barkiri, who disappears into the vast Danish marsh area.

At Marskgården, Nelly finds documents belonging to a terrorist group. Malu, who is on the run from Danish authorities and the murderer, is found by Helle, who then hides her. Two police officers find a gold icon in the marsh, which Malu lost during her escape. Art theft now becomes a possible motive for the killings.

Helle is hiding Malu from her boyfriend Morten, who has neo-Nazi sympathies. Nelly is facing problems with her son Buster, while trying to solve the case. Safa and Marwa, two of the victims in the murders at Marskgården, will be buried in Belgium. Paula hopes that Marva's boyfriend Karim attends the funeral, so that he can be questioned about the connection between the art theft and the terrorist group.

Helle and Malu seek refuge with Helle's mother, Ghita. Malu gets injured and is hospitalized. The police suspect that Morten is planning an attack. At the local hospital, an Arab man is looking for Malu.

Nelly is chasing the man who tried to kill Paula. The investigators gather for a briefing. They receive data from a Syrian mobile located at the German/Danish border, its location matches the man who tried to kill Paula.

The man who attacked Paula offers Malus's mother a lift. Gregor is on their trail. Malu has arrived at a safehouse. The press is informed of the 13 murders and Nelly shows footage of the assassin Said. Malus's mother finds out that Said is wanted for murder. Paula has found Karim.

Nelly and Gregor take Malus's mother to the safehouse, but Said arrives before they do. The police is investigating the illegal trade of antiques from Syria.

Richard Adams' illegal art purchase is revealed in the media. Malu tells the investigators about the gold friezes and the escape from Syria. The authorities work to extradite Malu to Syria, but Gregor will not let it happen. Paula is preparing to prosecute Richard Adams.