Damien and Leito return to District 13 on a mission to bring peace to the troubled sector that is controlled by five different gang bosses, before the city's secret services take drastic measures to solve the problem.
After a successful mission against drug lords, the efficient Captain Damien Tomaso is framed at home with three kilograms of heroin planted by the police in his kitchen and he is arrested. Meanwhile a group of teenagers film the action of dirty agents led by Roland from the security agency executing policemen in their car and then leaving the car with the corpses in the 13th District to blame the gangs and begin a civil war. Behind these events, the corrupt chief of the security agency Walter Gassman had received a huge amount as kickback from the constructor Harriburton that has interest to construct buildings in the poor area and uses the situation to force the President of France to authorize to nuke five towers in the district. The teenager with the film is hunted by the police but he delivers the memory card to Leito meanwhile Damien calls him from the precinct asking for help. The friends team-up with five dangerous bosses to gather evidences to prove to the president that Gassman has provoked the conflict in their district.—Claudio Carvalho, Rio de Janeiro, Brazil
Three years after the events of the original film (it is now 2013), the authorities are attempting to return law and order to ravaged District 13. However, their efforts so far have failed to do so. The Government changed and all the previous promises to restore District 13 and break the walls around it were forgotten.The death of gang overlord Taha Ben Mahmoud has left a power vacuum, and total control of the area is now being fought over by five rival territorial gang lords who want to step into Taha's position. All sorts of illegal businesses flourish inside District 13 including drugs, weed, gun running, hacking, stealing cars, protection money, extortion and so on.Each gang had their turf and their businesses which they protected fiercely.
Leito (David Belle) tries demolishing the walls surrounding the district on a daily basis but is told to stop by African gang lord Molko (MC Jean Gab'1), who sees the walls as protection from outside the district. Molko wants to protect his own dominion, where he is the King, and hence doesn't want things to change inside the district.
Damien (Cyril Raffaelli) a celebrated cop, eliminates a major drug dealer in Paris, by impersonating a prostitute and entering the dealer's inner circle at a bar that he operates. This way Damien is also able to incapacitate all of the dealer's major customers. Damien uses his team to extract the captured dealers and his major buyers through the sewer line running under the bar.Damien wanted to escape with an original Van Gough worth $200 million, but the painting was too wide for the sewer entrance, forcing Damien to exit through the front door and fighting all of the dealer's security. Damien fights through and destroys the dealer's drug lab located behind the kitchen of the bar.Damien manages to save the Van Gough and delivers it to the Louvre for preservation.But later, Damien is himself framed for drug dealing (A DISS unit raids Damien's apartment early morning and finds drugs in his home) and arrested but manages to make a brief call to Leito to come rescue him.
Meanwhile, corrupt government agents from the Department of Internal State Security (DISS), led by Walter Gassman (Daniel Duval) are bent on destroying the five tower blocks at the heart of District 13 with tactical precision bombing, and building luxury flats (they have taken a huge bribe from the builder to guarantee him possession of the land and building permits) after the area is cleared.
In order to spark conflict with the district's gangs, the DISS shoot two policemen, dump their car in District 13. This prompts several gang members into gunning down the vehicle, making it look like the gang members killed the policemen.The footage of the incident is shown to the French President (Philippe Torreton). The president wanted Damien to investigate the case, but he was already arrested. The footage is then played on national TV and sparks riots inside District 13. Many people cheer the killing of cops, but some can sense that this was a set up. As the situation spirals out of control (A police station inside the district is blown up with a grenade launcher), Gassman tries to convince the President to launch the strike. Gassman recommends evacuating the district in 12 hours and launching a direct strike on 5 apartment blocks that house the 5 gangs and most of their arms and drugs.
However, the DISS were witnessed killing the policemen and filmed by a teenager named Samir and his friends. Gassman and his team had looked at the CCTV cameras around the site where they killed the cops and saw that there was another car with people inside it, who were filming the whole incident.The DISS agents soon come after the teen to arrest him, but Samir manages to give his memory card to Leito before being arrested.Gassman finds out that Damien called Leito and sends his agents after Leito.
Leito watches the video on the flash drive given by Samir.Leito gets himself arrested in order to get into the prison. He then escapes the police and rescues Damien. After freeing Damien from his cell, they discuss the events (deducing that Damien was framed by DISS to keep him from finding out their plans during the crisis) and further plans, resolving to gather enough proof to expose the DISS agents.
While Damien distracts the guards, Leito breaks into Gassman's office to steal his hard drive for the evidence that they need. Once they escape and return to District 13, Damien and Leito convince the five gang lords Tao (Élodie Yung) (Asian Gang), Molko, Little Montana (Fabrice Feltzinger) (Gypsy Gang), Karl the skinhead (James Deano) (Skinhead Gang), and Ali-K (La Fouine) (Arab Gang) to band together and prevent the destruction of the district.
While the President struggles with the decision to destroy District 13, even with the area evacuated, a large number of gang members storm the Élysée Palace. They eventually reach the President and show him the information that they acquired, proving Gassman is a corrupt DISS agent. Gassman then takes the President hostage and tries to force him to approve the mass demolition. Leito, Damien, and the gang lords succeed in freeing the President and incapacitating Gassman, earning the President's thanks and a promise to fund District 13's restoration.
With the conflict over and District 13 completely evacuated, the gang lords then decide that it would be better to rebuild District 13 anew rather than try to patch up its remnants. The movie ends with the President authorizing the strike, the District 13 buildings exploding and the president breathing a sigh of relief, stating that he needs a drink.
In a post-credits scene, a short clip shows the President, the gang lords, Damien and Leito all joking around and smoking cigars together.
