When the mutilated body of a woman is found, police captain Laure Berthaud investigates. ..
With a second girl reported missing, police take in another suspect. .
With the second body identified, police delve into the depths of the Paris underworld. .
Police struggle to hold on to their suspect after he is hospitalised. .
Police manage to get the suspect remanded in custody, but revelations threaten their case. .
With the main suspect due to be released, Berthaud's team is now on the back foot. .
In spite of the evidence, Berthaud believes that the Butcher remains at large. .
With new evidence to back Berthaud's theories, Roban asks CID to be involved again. .
Police concentrate their efforts on putting Niko's prostitution ring under surveillance. .
Police tighten their surveillance operation, while the Butcher prepares to strike again. .
Police strive to connect the elusive leader of Niko's prostitution ring and the Butcher. .
Police close in on Niko's prostitution ring, but will Berthaud track the Butcher down? .