Léa is a strong person, but when she comes out of prison, she decides to get a fresh start. She would like to forget her cold and aloof father Vittorio Pastore, her young and irresponsible brother Samy for who she went in jail and the Zach's gang, the thug she used to love. But nothing elapses as she expected.

From his offices in Switzerland, Russian Igor Lipovsky is engaged in a vast and profitable gunrunning operation with Africa. The French government wants to hinder the activities of the arms dealer and sends a team to sink one of his ships heading for Angola with a load of illegal weaponry. Lisa, Brisseau, Loïc, Tony and Raymond are professionals: they carefully set up their cover, plan all their moves meticulously, and carry out orders without asking questions. Perhaps they should. The code-name of the mission is "Janus"; and just like with the ancient deity, there are two opposite faces for every aspect of the operation: the objective of the French government, the role of each team member, the presumed friend and the assumed foe...