The film Mauvais Sang functions primarily as a crime story, though the criminal element exists mainly as a framework. The narrative truly revolves around intense feelings of unreturned affection and the mental examination of those emotions. Lise is in love with Alex, who desires Anna, who herself is drawn to Mark. Meanwhile, Mark finds himself threatened by The American Woman—a former lover of his father—who will take action unless he settles outstanding debts for himself and his associates within a fortnight. A suppressed sexual drive runs throughout the story, intertwined with a peculiar affliction that impacts those involved in deceitful relationships; this element serves as a connecting thread for the entire film. Adding to the atmosphere is an unusual heat wave linked to the presence of Haley's Comet. The movie is rich and complex, and its French origins are evident in the actors’ expressive physical performances. While some scenes may feel over-the-top and not resonate with everyone, other moments more than compensate for them.

Source on TMDB