The series follows the adventures of lighthearted Jean-Paul Moulin, a police Commissaire, and his team as they solve crimes.

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.

In this thriller, a UNESCO translator stumbles across a group which is hiding and supporting Nazis and facilitating their travel around the world. She had been given an assignment to study the work of a writer who recently had died, and the conspiracy is revealed in materials he left behind. She comes upon a young man who is going through the writer's papers, and she immediately assumes he must be one of the conspirators. However, he soon convinces her of his innocence in that regard, and the two together begin a search for the ringleader.