Professor Charles Buisson, astronomer and Nobel Prize winner, has just discovered a nova. He informs the other observatories by telephone. Just as he thinks one of them is calling back, he finds himself on the line with a young woman threatening suicide at the Ruban Bleu cabaret, if her lover hasn't joined her by midnight. Intrigued, the professor decides to go and prevent the unfortunate woman from committing suicide. One of his students, who earns her living as an understudy in a knife act, helps him in his investigation, while the school principal and a policeman suspect him of being a prankster or even of selling drugs. For the scientist, it's an opportunity to discover a world of music-hall that he'd never known before: "I thought I knew the sky chart by heart, but there's one planet that was totally unknown to me: Earth. I'll be back!

The film consists of seven roughly 15 minute episodes, each showing what will happen if one or more of the Ten Commandments will be broken: Jérome Chambard is warned that he will lose his job if he continues to swear; Françoise Beaufort enamored of a stripper calls on her only to find her married to a janitor who doesn't know what kind of dancing his wife performs; Denis, a Jesuit novice, leaves the order to avenge his sister's suicide, which was provoked by Garigny, who seduced her into prostitution and drug addiction; Philip buys a necklace for Micheline though he is bored with her; a young man find out that his real mother is not Madeleine, but actress Clarisse Ardant; Didier Marin, cashier of a bank, was fired by his boss; the Devil appears as a serpent for Jérome Chambard and the bishop are eating.

A female journalist beats two male rivals to a scoop by exposing a white slave racket going on right in 50s Paris.

A do gooder hopes to cure potential romantic partners of what he considers the disease of love, by putting them up in a property and having them watched over.Things do not turn out according to his plan.

An old woman living in an inn is killed and her family members seem like the likely culprits.

Following a trivial road accident, Ariane, an international adventuress, falls in love with Bernard Fleuret, a young artist-painter with diseased lungs. Being pursued by the police, she chooses to hide in the sanatorium where the young man is treated. Ariane proves so smitten by love that she finally changes her ways: she decides to let herself be arrested, sure as she is she will be reunited with her loved one later on.

In the heart of Paris, a restaurateur's mundane life is disrupted by the arrival of his ex-wife's daughter, who claims to be in need after her mother's death. After marrying her, tensions rise when she becomes involved with a young student, leading to betrayal and murder. As secrets unfold, he uncovers the truth about her past and her manipulative nature.

Sylvain, sentenced to death, assures the visiting priest that his life could have been completely different, and invents different situations.

Agnès Bonnardet leaves her parents to marry Claude Sironi, a painter who becomes famous but loses his talent. Meanwhile Agnes acquires a style of her own as an artist, which makes Claude jealous of his young wife. One day, he sends one of his own paintings to the Bazar de la Charité, a very trendy Paris department store, instead of one of his wife's works as ordered. Afraid of her being mad at him, he locks her up in the cloak room. A dreadful fire suddenly breaks out and sets the building ablaze.

Being born a witch's daughter did not bode well for your future in the Middle Ages. Guillaumette tries to stay on the straight and narrow with a little help from a priest she visits.