Sam, a freelance journalist, leads an investigation about integriste environments from the outskirts of Paris. For more than six months, Sam takes advantage of its Muslim culture to infiltrate in those environments. In an underground mosque, Sam sympathizes with Sidi Driss, and Christophe, three young men without landmarks, prepared at any moment for a jihad. One day, the mysterious H announces that they received them as creating a mission for Al-Qaida cells and to sow chaos in the streets of Paris. Panicked, Sam rushes to inform the police of the existence of this dangerous cells. Without his accomplice, is forced to communicate these facts and gestures police terrorists.