When the young detective Paul Nerteaux finds the third slashed female corpse of illegal Turkish immigrants, he decides to ask for support to the experienced dark retired detective Jean-Louis Schiffer to chase the serial killer. Together, they infiltrate in the Turkish mafia trying to find the answer to the crimes. Meanwhile, the worker Anna Heymes is being submitted to a brain treatment and has severe headaches and glimpses of memories and visions. When these two parallel events collide, disclose that the Turkish organization "The Wolves" is behind them.

When the young detective Paul Nerteaux finds the third slashed female corpse of illegal Turkish immigrants, he decides to ask for support to the experienced dark retired detective Jean-Louis Schiffer to chase the serial killer. Together, they infiltrate in the Turkish mafia trying to find the answer to the crimes. Meanwhile, the worker Anna Heymes is being submitted to a brain treatment and has severe headaches and glimpses of memories and visions. When these two parallel events collide, disclose that the Turkish organization "The Wolves" is behind them.

In France, the single translator Diane Siprien adopts an Asian baby named Liu-San in a foundation directed by Sybille Weber. Years later, a weird mark appears on the boy's chest and Diane and Liu share their dreadful nightmares. Diane is assigned for a three-day job in Germany and she leaves Liu with her friend Sybille. However, while going to the airport, Diane finds Liu hidden in the backseat and startles with an eagle flying toward the windshield, crashing her car. Liu falls into a coma and his digital recorder records the boy speaking in an unknown dialect. When Diane searches the translation and the origins of Liu, she is surrounded by mysterious murders. She discovers that the dialect is from the mystic Mongolian Tseven tribe and that Liu is a powerful Observer; further, he is in danger, threatened by sorcerers that need the boy for their Council of the Stone..

Paris, 1830. In the heart of the town, Vidocq, a famous detective, disappears as he fights the Alchemist, an assassin that he has been pursuing for a few months. His young biographer, Etienne Boisset, decides to avenge Vidocq's death and takes the investigation on...

In Montreal, the unemployed fashion designer Sophie Malaterre is shown a website, switch.com, where it is possible to switch houses with a stranger for vacation. Sophie seeks an apartment in Paris nearby the Eiffel Tower that belongs to Bénédicte Serteaux and they change apartments. Sophie arrives in Paris on Saturday morning. The next morning, policemen break in the apartment and arrest Sophie while she is having a bath. Detective Damien Forgeat interrogates Sophie believing that she is Bénédicte and she learns that a beheaded body was found in her room and all evidence of her life has been deleted.

Paris, December. A conductor of a choir is found mysteriously murdered, with burst eardrums. Lionel Kasdan, a police inspertor the verge of retirement, and Frank Salek, an official of Interpol, embark together on a hunt for the killer, and also to a secret organization specializing in kidnapping children.

No one is safe when seemingly random killings emerge as a deadly pattern intended to usher in the end of the world. A murder victim with the same DNA as Christ. A serial killer mimicking the deaths of the 12 Apostles. Inspector Niemans and a young, rebellious detective team up with a beautiful expert in religion to crack the case before their elusive suspect completes the cycle of terror, paving the way to an even bigger bloody catastrophe.

In Montreal, the unemployed fashion designer Sophie Malaterre is shown a website, switch.com, where it is possible to switch houses with a stranger for vacation. Sophie seeks an apartment in Paris nearby the Eiffel Tower that belongs to Bénédicte Serteaux and they change apartments. Sophie arrives in Paris on Saturday morning. The next morning, policemen break in the apartment and arrest Sophie while she is having a bath. Detective Damien Forgeat interrogates Sophie believing that she is Bénédicte and she learns that a beheaded body was found in her room and all evidence of her life has been deleted.

Two French policemen, one investigating a grisly murder at a remote mountain college, the other working on the desecration of a young girl's grave by skinheads, are brought together by the clues from their respective cases. Soon after they start working together, more murders are committed, and the pair begin to discover just what dark secrets are behind the killings.