The film was inspired by the events of the French Connection in the 1970s, starring Jean Dujardin as police magistrate Pierre Michel (juge) and Gilles Lellouche as Gaëtan "Tany" Zampa, a drug gang ringleader.

Following a tip given by one of Michel's informants, the heroin-addicted teenager Lily, they arrest Charles Peretti, an old Corsican chemist who formerly produced heroin for la French.

Enraged by Tany killing his informers and because he can find out nothing relevant about the gang, Michel orders all lower cadres of la French arrested, "cutting the octopus' arms".

While surveilling one of Marseille's casinos controlled by the gang, Michel has a short look in a side room and sees one of the leading figures of the narcotics squad, police veteran Ange Mariette, chatting with Zampa.

Pressing the younger cop Alvarez, Michel finds out that Mariette is the leader of a large gang of corrupt Corsican police officers.

[6] Reviewer Ty Burr from the Boston Globe called the film "...a stylish affair, very solidly made if not exactly breaking new ground in our understanding of events or in the way the movies depict them" and gave it a 2.5/4 score.

[6] Robert Abele from the Los Angeles Times stated that "[d]espite the pedestrian screenplay (by Jimenez and Audrey Diwan), Dujardin and Lellouche are magnetic performers who slip easily into their antagonistic roles.

[6] Alan Scherstuhl from the Village Voice stated that the film is "...engaging, propulsive, cut with rare brio, chockablock with consummate tough-guy business.

"[6] John DeFore from The Hollywood Reporter calls the film a "...procedural epic whose complicated narrative is propelled by visceral action sequences and an unusually thrilling soundtrack.