Director: Henri-Georges Clouzot
Cast: Simone Signoret (Nicole Horner ), Vera Clouzot (Christina Delassalle, and Paul Meurise (Michel Delassalle). Released in 1955, Les Diaboliques, shocked theater audiences with not only the premise of the plot but also in the stark images of death and the macabre notes of horror that make this a classic must-see murder mystery.
Simone Signoret portrays Nicole, the bitter and angry mistress of the headmaster at the boarding school where she teaches. Nicole is convinced that she must murder her lover in order to free herself from his sadistic cruelty.
Nicole is not alone in her hatred for her lover, Michel Delassalle. His own wife, Christina, who is also a teacher at the boarding school, is filled with loathing for her husband, as well. She has suffered in silence during his beatings. She has cringed under his verbal abuse and she has been humiliated by Michel's open affair with the lusty, but jaded, Nicole.
The two women should be enemies but they are united by their mutual hatred for a man who has so cruelly ruined both of their lives.
Christina does not have the strength and passion of Nicole but she conspires with her husband's mistress to kill him, although she is horribly afraid. Nicole has a weak heart and has been abused for so long by her husband that she wonders if she can go through with Nicole's plan to kill Michel.
Vera Clouzot, wife of the film's masterful director, is perfectly cast as the long-suffering and ailing wife. Her eyes grow wide with hate and fear and her frail body seems ready to crumble under the anxiety of the bizarre triangle of death that she has become a part of.
Somehow, Christina finds the nerve to go along with the Nicole's murderous scheme to kill Michel. He is lured to an apartment and drugged with whiskey that has been spiked with powerful sedatives. Even though he is drugged and helpless, the two women struggle to drown Michel in a bathtub. Together, they have to push their victim's head down into the bath water again and again, until there is no sign of life left in his body.
Nicole and Christina now must hide Michel's body according to their agreed-upon plan. They wrap the corpse and return to the boarding school where they slide the headmaster's body into the murky water of an old swimming pool, which is no longer used. There, in his watery grave, the women hope that the headmaster's body will remain hidden for months until the pool is drained in the summer.
Death doesn't stay lying down quite as easily as Nicole and Christina believe. Haunted by guilt, fear, and the horror of the murder they have committed together, both of the women begin seeing visions that are frightfully all too real. Adding to their terror is their discovery that when the swimming pool is ordered to be immediately drained ... the corpse of Michel Delassalle has vanished!