In Paris, police search for a psychopath whose murders are inspired by Jeanne Deber, known as "The Mantis", a famous serial killer who terrorised the country 25 years ago. Jeanne Deber offers her expertise to the police in order to help hunt the copycat. Placed in solitary confinement since her arrest, "The Mantis" has one condition: to deal only with Detective Damien Carrot, her estranged son. Damien has no choice, for a serial killer is on the loose and could strike anytime, anywhere in Paris.
This series provides examples of:
- Asshole Victim: Early in the series, it's stated that the victims of "The Mantis" were all assholes fathers, either violent, incestuous or just abandoned their family.
- Jack the Ripoff: A serial killer starts a killing spree using the exact same methods as a known serial killer.
- Parental Incest: It's revealed in the final episode that Jeanne's father had raped her when she was a child, and said rape was one of the major reasons why she became "The Mantis."
- Red Baron: Jeanne Debber, who is known as "The Praying Mantis" or sometimes, just "The Mantis."
- Vomit Discretion Shot: One of the first scenes in the series has a cop leaving the room where they found a murder victim and quickly throws up behind a wall.
