When the body of a young woman is found murdered and mutilated, police captain Laure Berthaud seizes the opportunity to redeem a tarnished reputation and leads her squad on the hunt for the sadistic killer. Meanwhile, Judge Roban’s investigation into the case of a child being bitten by a dog might turn out to have broader implications, and even public prosecutor Pierre Clement is not immune from the resulting pressure.
With a second girl reported missing, police take in another suspect. Given a troubling track record, it is essential that Laure Berthaud keeps her team under control, but how easy will that be when her own grip is starting to slip? Public prosecutor Pierre Clement pays the price for refusing to cave in to pressure from above, Judge Roban’s investigation into possible curruption also causes discomfort in high places and ambitious barrister Josephine Karlsson also finds herself the target of an act of vengeance.
With the second body identified as that of missing girl Celia Morau, police believe that they could be looking for a serial killer and delve into the unsavoury depths of the Paris underworld in their search for clues. The pressure piles on, with Judge Roban threatening to hand the case over to the Serious Crime Squad in the absence of prompt results, and Captain Laure Berthaud is on the brink of mental instability when an important breakthrough occurs.
Police struggle to hold on to their suspect after he is hospitalised. Meanwhile, believing that the killer may still be at large, prostitutes exploited by an organised ring are terrified to work the Paris streets. Judge Roban’s judgment risks falling prey to the tyranny of emotion as friction between his professional and personal life starts to make itself felt. And former public prosecutor Pierre Clement joins the bar to partner up with talented but unscrupulous solicitor Josephine Karlsson.
Police manage to get their suspect remanded in custody, but a series of unexpected revelations threatens to jeopardise the solidity of their case. The infamous accused, by now known as the Butcher of La Villette, is defended by none other than the fearsome Josephine Karlsson. Judge Roban’s uncharacteristically hasty actions are thought to compromise his impartiality. Settling in his new role as barrister, Pierre Clement finds himself roped into dealing with an unusual case.
With the main suspect due to be released and an alarming number of procedural blunders stacking up on the record, Captain Berthaud’s team is now on the back foot. When Judge Roban transfers the case to the Crime Squad, Laure’s reaction is surprising, but she remains doggedly determined to catch her killer. Josephine Karlsson’s shady past connections return to haunt her, and Judge Roban realises the extent of his brother’s involvement in the Villdieu bribery case.
In spite of the evidence, and of protestations from members of her team, Captain Berthaud continues to believe that the Butcher of La Villette remains at large. At the same time, Bremont grows suspcious of her affections. Clement defends a young offender with a troubled past and feels sorry for him, while Judge Roban ploughs on with his corruption enquiry, sparing no-one in the process.
With strong new evidence to back Captain Berthaud’s theories, Judge Roban asks the CID team to become involved in the investigation again. But how will Laure deal with having to play second fiddle to work rival and lover Superintendent Bremont? Police are out to substantiate a link between the leader of an international prostitution ring and their main murder suspect. Judge Roban’s pupil Arnaud finds himself the target of blackmail.
Police concentrate their efforts on putting Niko’s prostitution ring under surveillance, in the hope of tracking down the man who is now an essential link in the investigation. Bremont puts the pressure on Gilou, and Laure jeopardises everything to help her colleague. Roban starts to suspect that someone may have betrayed him. Pierre attempts to distance himself from Dylan, but is in for a nasty surprise.
When he unwittingly finds himself on the wrong side of the law, former public prosecutor Pierre Clement turns to none other than the best – and most unscrupulous – lawyer he knows. Police tighten their surveillance operation on Niko’s prostitution ring, while the Butcher of La Villette prepares to strike again. And Judge Roban finally discovers hard evidence to support his enquiry into municipal corruption.
Police strive to pinpoint the connection between the elusive leader of Niko’s prostitution ring and the Butcher of La Villette, who is still on the run. There is more tension between Laure and Gilou, as Gilou prepares to leave the team. Judge Roban finally gets proof of Arnaud’s betrayal and his reaction is unforgiving. The screws tighten on the Courcelles bribery investigation. Szabo finds Josephine’s Achilles’ heel and uses it to blackmail her back into his clutches.
The police finally close in on Niko’s prostitution ring, but the Butcher of La Villette is still evading custody. Will Captain Berthaud manage to track him down? Will Niko’s men get to him first? Or will he get the opportunity to kidnap another victim? Judge Roban finds that the high moral ground comes at a high price. Pierre discovers that Josephine has made a deal with Szabo in order to save him.