The first true arthouse hit, Diabolique was based on the novel Celle Qui N'etait Pas, a thriller written by the French writers Pierre Boileau and Thomas Narcejac.

The title roughly translates as The Woman Who Was No More. Boileau and Narcejac often patterned their novels after the works by American authors such as James M. Cain - but with an added twist at the end.

Feeling that the material would be perfect for Alfred Hitchcock, they approached the esteemed director but the deal fell through. Hitchcock was known for paying low sums for the rights to stories and novels...and that may be the reason the job went to Henri-Georges Clouzot.

Clouzot cast his wife in the main role of Christina, retitled the film Les Diaboliques ("The Devils") and the rest is history. Ironically, Les Diaboliques would prove to be a major influence on Hitchcock, especially on his most famous film, PSYCHO.

Hitchcock would also borrow Clouzot's very successful ad campaign, which encouraged audiences not to reveal the ending - and theatres not to let people in after the film had started. Perhaps not wanting to miss another opportunity, the Master of Suspense snapped up the rights to Boileau and Narcejac's next thriller, D'entre les Morts, which he would film as Vertigo.

The setting is the Delassalle Boarding School for boys in Paris. It's a somewhat dilapidated institution and is run by the tyrannical headmaster Michel Delassalle (Paul Meurisse). Nicole Horner (Simone Signoret) is a teacher there. During lunch recess, one of her colleagues, M. Drain (Pierre Larquey)...notices she is wearing sunglasses indoors.

He asks her what happened and adds that he heard screaming coming from her room the night before. Nicole responds by telling him that she hurt herself in an accident. The weekend is coming and she informs another teacher that she is going to spend time at her home in Niort.

Christina Delassalle (Vera Clouzot), a Spaniard, is Michel's wife and also a teacher at the school. It is her money which actually funds it. In a conversation with Christina, Nicole wonders how Christina can stay with Michel. She also shows his wife the black eye which she received the previous night. It is an open secret at the school that Michel is carrying on an affair with Nicole while still married.

Together, the two women commiserate about the abuse he heaps on the both of them...and Nicole confesses to Christina that her husband only married her for money. At that point, Michel walks into the room and taunts the two. He refers to his wife...who has a medical condition, as a "little ruin."

Sitting by the pool, Nicole and Christina discuss a plan to get back at Michel. But Christina is reluctant. At supper, Michel again proves to be insensitive by serving the staff and the children bad fish. He says it's to save money and humiliates Christina by forcing her to eat the food. This makes the students agitated and they react by banging their utensils on the table. Michel sends them all up to their rooms.

Enraged, Christina confronts Michel and tells him that she is paying for everything and that it upsets her to see the students treated like that. She even says she'd like to die, to which Michel responds "Die, and do it quickly. We'll have a nice funeral for you and we'll get rid of you."

Nicole gets up to go to bed and whispers in Christina's ear that she's leaving at 7am for the long weekend. With the mistress out of the room, Michel then forces himself on his wife.

The next morning, Christina sneaks out of her bedroom while Michel is sleeping. She takes her suitcase and meets Nicole at the garage. Nicole prepares a large wood trunk to take with them. Michel finds out at breakfast that the two women have left together.

As they drive to Nicole's house in the town of Niort, Nicole and Christina discuss their plan to murder Michel. Nicole admits that Michel was in fact hoping that his wife's heart condition would give out - and that he would inherit the school from her.

When they get to the house, they are met by one of Nicole's tenants, Mme. Herboux (Therese Dorny). The women are tired from traveling and they go directly to one of the rooms along with the trunk.

Together, they place a call to Michel. Christina tells him she wants a divorce and that she's taking the school from him. Michel says that he will take a train to Niort to talk to her the next morning. The trap is set.

At dawn, Nicole leaves the house and returns with a waterproof tablecloth and a bottle of wine. She empties out some of the liquor and replaces it with drops of a liquid sedative. Christina is a deeply religious woman and is nervous about their plan. She tries to chicken out but Nicole convinces her to go through with it.

Nicole heads up to the Herbouxs' to distract them from seeing Michel arrive. He gets to the house and Christina greets him. He is upset and considers it embarrassing that he had to sneak out of the school in order to come see her.

When his wife tells him that she has seen a lawyer, Michel threatens to go speak to him right away. Christina admits that she made it up but she still wants a divorce. As they talk, Michel pours himself a drink. Christina tries to knock the drink away from his mouth but ends up spilling it on his suit. This makes him angry and he slaps her.

Michel tells her to wipe his jacket clean and after this last act of meanspiritness, Christina decides to let him drink the liquor after all. Before long, he becomes drowsy. Nicole hides in the bathroom...filling the tub with water as Christina burns his return ticket.

Meanwhile, the running water is making noise in the pipes and disturbing the tenants above. M. Herboux (Noel Roquevert) has a fit because he can't hear his radio program.

The tub is now filled and Michel has passed out. Christina and Nicole carry him over to the bathroom and put him in the tub. He wakes up and Nicole shoves his head under the water. Because of the drug, Michel barely struggles and drowns.

His wife is in shock and Nicole has to prod her into getting a heavy bronze statue from the mantel. They use it to weigh his body down under the water. Christina is so shaken she begins to have chest pains and has to rest on the bed. Nicole calmly gets the tablecloth and covers the tub with it.

The next morning, they load Michel's body into the trunk. Nicole tells M. Herbroux that she is taking her dishes back to the school - and he helps her load the trunk into her car. The Herbrouxs will be the perfect alibi.

Nicole and Christina arrive at the school in the evening and are let in through the gates. Near the pool, they open the trunk and take Michel's corpse out - which they dump into the water.

While teaching a class the following day, Christina is unable to stop looking out the window. She keeps checking on the pool and becomes nervous when she sees the groundskeeper pull trash from it. She also finds it difficult to grade papers. Nicole tells her that she will have the pool emptied the next day if the body doesn't come up.

When a ball that the boys are playing with goes into the water, Nicole and Christina decide to let the corpse be discovered. A boy who dives into the pool finds Michel's lighter...and Christina tells M. Plantiveau (Jean Brochard) to drain the pool. She waits impatiently in her classroom and then runs out towards the pool. She looks down into it and faints. There is no body!

A doctor treats Christina and she is given medication for her condition. Nicole tells her that someone must have taken Michel out of the pool. She has searched everywhere and there is no trace of him. The women are spooked even more so when M. Plantiveau brings them Michel's suit, which a man from the dry cleaners delivered back to the school.

At the cleaners, the laundry woman describes the man as tall and dark...and pulls out a key which he left behind, belonging to the Eden Hotel. Nicole says they should forget about it because someone wants to blackmail them - but Christina insists on going to the hotel. She goes up to the room by herself and finds a cleaning guy who tells her that M. Delassalle is never there during the day and in fact, he has never seen him.

Christina begins to regret her part in the murder. When she threatens to go to the police and blames Nicole for the situation, Nicole tells her she had just as much to do with it. They're both somewhat relieved when they see a headline in the paper which reads "A Naked Corpse in the Seine."

It seems obvious that Michel's body has been found. But that relief doesn't last for long. When Christina goes to the morgue to identify the body, she realizes they were wrong. Little does she know that someone is following her.

Outside, the stranger introduces himself to her. His name is Alfred Fichet (Charles Vanel) and he's a retired police commissioner. He offers her a ride back to the school and she accepts. M. Fichet insists on helping find her missing husband.

At the school, M. Fichet questions M. Plantiveau to no avail. Christina pretends that she overreacted at the morgue and tries to pay M. Fichet for his services. He declines and continues his investigation by asking questions about Michel's physical attributes.

The inspector inquires about what Michel was wearing when he disappeared and Christina tells him they were out of town at the time - so they wouldn't know. Next is an inventory of his clothing. Just as Christina is telling Fichet which suit of Michel's is missing from the closet, they see it hanging behind the door. Christina feels faint and has to sit down.

In the school yard, the women see one of the boys working. When Nicole asks him what he is doing, he tells her that the principal punished him. Nicole strikes the boy for lying but Christina tries to be gentle with him.

Again, the boy claims that Michel Delassalle put him to work for breaking a window with a slingshot - which he then confiscated. The teachers scoff at the boy and call him delusional. M. Drain punishes him for his dishonesty.

The slingshot does indeed show up at the school and Christina has become paranoid that their crime will be discovered. First the suit, then the hotel - and now the students. She feels ill from the stress and can't attend a photo shoot for the faculty and students.

When the photo is developed, Nicole is horrified to see an image in the window behind the group. It appears to be Michel. She pleads with Christina to leave the school and go away with her. But Christina decides to stay and face the consequences. Nicole leaves by herself.

Inspector Fichet enters Christina's room to question her. Thinking she is about to be exposed, she confesses everything to him. Fichet tells her to take a sedative and that she will be aquited in the morning. Still trying to figure everything out, he examines Michel's lighter which was found in the pool as well as the wood trunk they used to carry his body in.

Christina attempts to fall asleep - and all the lights are turned out in the school. Hearing something outside her room, she gets up to see what it is. A light is visible at the end of the hallway, coming from Michel's room.

As she approaches, the sound of typing becomes audible. Now she is frightened and sweating profusely. She enters the room and sees Michel's hat and gloves on the typewriter. When she takes the paper out, Christina reads what is on it.

Someone has typed the name Michel Delassalle over and over. Just then, the light in the room goes out and Christina screams. She runs down the hall and into the bathroom, where she throws water on her face. Turning around, she sees a frightening sight. Michel's body is submerged under water in the tub. He slowly starts to get up. Only the whites of his eyes are visible. This is too much for his wife and she suffers a fatal heart attack.

The Terror Trap normally reveals the plotline down to the end. In the case of Les Diaboliques, we will respect the director's wishes.

At the very end of the film, Henri-Georges Clouzot states:

"Don't be devils. Don't ruin the interest your friends could take in this film. Don't tell them what you saw. Thank you for them."

When this movie was released in 1955, Americans lined up around the block for the first time to see a foreign film.

The film's perverse atmosphere and dark humor make it a must-see. The lead performances are all incredible, particularly Clouzot's wife Vera...entirely believable as the vulnerable lead.

Many have tried to rip off the story's twist...with much less creativity and sincerity. A timeless classic.