This series is definitely one of the best cops/crime series ever, whatever country. It was strange how I completely forgot there were subtitles, it was like a seamless cross-over to French which I do not speak.
Acting by all is superb, especially Jean-Claude Anglade the charismatic head of 4 cops who get the bad guys seemingly through any means possible including the illegal. Interesting shots of a mostly depressing Paris which matches the mood of the numerous high level and low life criminals. Shows complicity of French politics with corrupt cops. Several stories happening at once so tension remains high even when one case is resolved. Creative and unpredictable moves on part of the police and criminal. Not like white-bread formulaic American cops and crime shows.
I watched all four seasons, binge style. I was sad when it was over, can't think of a way to have another season. Too bad, back to the mostly futile search through the scads of crap shows on TV or internet (except of course the truly excellent like Breaking Bad, Please call Saul, Six feet Under, Sopranos.... Renewed hope in me that great drama is not dead.