Fabienne is a police officer. She does her job well but is gradually growing tired of the dehumanized nature of her work : arresting undocumented aliens day after day does not fit in with her ideals. That's why when, one night, Olga, the Kazakh prostitute she apprehends, begs her to free her not to leave her four-year-old son alone, she hesitates... And why, after Olga has run away and is found dead, Fabienne decides to deal with this matter personally...