Someone is killing Parisians of Arab ethnicity. When an Algerian diplomat is murdered by the same assailant, two Algerian detectives are sent to help the French with the investigation and they have their own ways of doing things.

Karma tells the story of a group of three childhood friends: Koffi, Chris, and Ahmess. While building his career as a rapper, Ahmess decides, on the advice of his two companions, to stop his illegal activities. But unfortunately, the streets and certain past events catch up with them...

When a team of explorers venture into the catacombs that lie beneath the streets of Paris, they uncover the dark secret that lies within this city of the dead.