Franck Poupart (Patrick Dewaere) is a door-to-door salesman. His wife Jeanne (Myriam Boyer) leaves him after he knocks her into a bathtub filled with water after she refuses to make him dinner following one more rant about their dire situation. Then he gets imprisoned for embezzlement. Mona (Marie Trintignant), an underage prostitute, bails him out and persuades him to rob her rich aunt (Jeanne Herviale). Poupart kills the aunt, and then murders his accomplice to frame him for the crime.
However, his streak of bad luck ("série noire" in French) continues, for his wife returns, unannounced and pregnant, and suspects him of murder. He murders her, and then his boss robs him of his booty, leaving him alone and broke with the besotted Mona.
Série noire provides examples of the following tropes:
- The '70s: Made right at the end of the decade, with the cars, clothes, haircuts and music (such as Claude François) looking and sounding accordingly.
- Adaptation Name Change: The protagonist is named Frank "Dolly" Dillon in the book, and Franck Poupart here.
- all lowercase letters: There are no caps in the opening credits' names.
- Awful Wedded Life: It's pretty clear that, if Franck and Jeanne ever loved each other, that has faded away. They've never been able to become homeowners, living in one slum after another, and it all ends on yet another dispute.
- Dancing with Myself: Franck dances alone outside of his car during the opening credits, for no particular reason.
- Enemy Eats Your Lunch: When Franck is at a bar, a drunk leather jacket-wearing hooligan drinks his beer right in front of him, then forces himself on Franck's mouth.
- From Bad to Worse: Franck's situation, from an Awful Wedded Life to going to prison for embezzlement and then committing murder.
- Honest John's Dealership: Franck starts off as a door-to-door salesman who can say such silly things as "Austrian wool straight from the Pyrenees" (the latter are the mountains separating France from Spain) with a straight face.
- Kitchen Sink Drama: Franck and Jeanne have been married for some time, and they've never been able to become homeowners, instead living in one slum after the other. Jeanne leaves after one more dispute where she ended up shoved in the filled bathtub by Franck.
- No Name Given: The name of Mona's aunt is never pronounced.
- Sex for Services: The woman Franck sells a bathrobe to at the beginning offers to pay him with an "intimate moment" in the company of her 16 year old niece Mona... Franck follows Mona in her room, then she completely undresses right in front of him. Probably feeling a Jail Bait due to her age (and being married at this point), Franck quickly has her dress up again and lectures her.
- Speeches and Monologues: Franck monologues quite often at the beginning.
- Stealing from the Till: Franck steals money from his business, which gets him denounced by his boss and imprisoned for a few days.