Hélène, a fragile and romantic teenager, discovers that her father, a rich business man, has a mistress. Curious, she decides to go and meet this woman who is described as strange. At the first chance she has she goes to her house in the Ramparts of Béguines... from then on she goes back often, discovering a new world of artists and nightowls where she also experiences love in the arms of Tamara.
Francois, seducer very misogynist, directs an Eros Club, that from which suffers his Carole wife silently. Julie, saleswoman in a clock industry, as for it is taken of an access of madness after having surprised her husband, Léo, future
The "black robe" in the title of this suspense film belongs to a female lawyer, Florence Nat who has just lost a case in which she defended Simon Risler, a man wrongly accused of murder. Risler escapes before he can be put in prison, and seeks help from attorney Nat in finding the real killer, partly by going after the police inspector who framed him in the first place. A retired surgeon, in the process of setting up a drug rehab clinic gets involved in solving Risler's case, and soon the solution seems to be pointing to high-ranking figures with every desire and ample means to keep the truth well-hidden.
