Frank and Bill, two Beverly Hills ambulance drivers, arrive at the Tremayne mansion, where Catherine Tremayne has been affected by gas poisoning but has already been treated by the police. When Frank tries to reassure Catherine’s stepdaughter, Diane, she becomes hysterical, causing them to trade slaps. After they leave, Diane follows Frank to a diner, where they flirt and decide to go to dinner, despite of Frank already having a girlfriend, Mary.
At dinner, Diane tells Frank about her father, and Frank tells her about Mary. We learn that Frank had been a race-car driver, and that Mary was saving up money in order to help Frank to buy his own garage. The following day, Diane meets with Mary under the pretense of contributing to Frank’s garage. In reality, she wants to make Mary jealous by letting it slip that they had dinner the prior evening.
Mary loses confidence in Frank and agrees to go out with Bill, an old boyfriend. Frank tracks down Diane to berate her about telling Mary about their impromptu dinner. But when she tells Frank he can work at the estate as the chauffeur, as well as prepare and drive her sportscar in an upcoming race, Frank forgets about what she has done. Diane convinces her parents to hire Frank as chauffeur and let him live in a small apartment on the estate grounds. She further ingratiates herself to Frank by getting her stepmother Catherine to agree to listen to Frank’s proposal about investing in a garage. The two begin a romantic involvement.
While Catherine is awaiting advice on Frank’s proposal from her attorney, Diane lies to Frank, telling him that Catherine wants nothing to do with the project. She further attempts to alienate him from her stepmother by saying Catherine would fire Frank if she ever found out about his and Diane’s romance and that Catherine would take it out on both her and Diane's sickly father if she were being defied. Diane claims Catherine even attempted to kill her by turning on the gas in the fireplace. Frank suspects Diane is lying.
Frank goes to Mary and says he is getting out of both the chauffeur job and romantic entanglement, after which they reconcile. But when he goes back to the Tremayne estate to get his gear, Diane cries and begs him to run away with her. He is confused enough to agree to stay for a few more days, but will no longer work as the chauffeur.
Catherine is about to drive herself to a bridge tournament, and Diane's father Charles asks for a ride to town. Instead of moving forward as expected, the vehicle speeds in reverse, crashing through a guard rail. It careens down a steep cliff, killing them both Diane now being the sole heir, she comes under suspicion for murder; police arrest her and Frank as well. Diane is devastated as she never intended her beloved father to be in the car and is admitted to a hospital for treatment. She confesses that she planned and executed the murder. Doctors believe she is delirious.
Defense attorney Fred Barrett warns Frank that he will take the rap since Diane's suitcase was found in his room. He suggests Frank and Diane marry, which means they cannot be compelled to testify against one another. This could allay suspicions as to why Diane and Frank were both packed to leave.
The tactic works. Barrett is able to convince the jury that Frank and Diane are simply lovebirds caught up by circumstance and they are both acquitted. This despite expert testimony of evidence the car's drivetrain was tampered with before its crash.
Frank tells Diane he wants no part of her and will try to get Mary to take him back. Diane scoffs that Mary won't and bets her car on it. Mary refuses him, saying she will stay with Bill. While this is happening, Diane goes to attorney Barrett and confesses everything. He allows her to unburden herself, then informs her she can no longer be convicted since double jeopardy is attached.
When she returns to the mansion, Frank is packed to leave and has called a taxi. She begs Frank to take her to Mexico with him, but he says no. Frank reluctantly agrees to let her drive him to the bus station. In the car, she gives him a steely look, then quickly shifts the car into reverse and steps on the gas pedal, sending them careening to their deaths over the same cliff where the previous murders occurred.Robert Mitchum as Frank Jessup
Jean Simmons as Diane Tremayne
Mona Freeman as Mary Wilton
Herbert Marshall as Charles Tremayne, Diane's father
Leon Ames as Fred Barrett, Frank and Diane's defense attorney
Barbara O'Neil as Catherine Tremayne, Diane's stepmother
Kenneth Tobey as Bill, Frank's fellow ambulance driver
Raymond Greenleaf as Arthur Vance, Catherine Tremayne's estate attorney
Griff Barnett as judge presiding over the trial of Frank and Diane
Robert Gist as Miller, forensic expert on automobile mechanics who testifies during the trial
Morgan Farley as inquisitive juror who asks two questions during the trial
Jim Backus as District Attorney Judson, in charge of prosecuting Frank and Diane
Amzie Strickland as Woman in dance hall, alongside Frank and Diane
Lucille Barkley as Waitress serving Frank and Diane
Lewis Martin as Police sergeant on duty when Frank is brought in
Larry J. Blake as Detective lieutenant Ed Brady who advises Frank to hire himself a lawyer
Gertrude Astor as Prison matron addressed as "Sergeant"
Theresa Harris as Prison nurse Theresa who is assigned to Diane's bedside
Grandon Rhodes as Prison chaplain who performs Frank and Diane's marriage
Frank O'Connor as Bailiff at Frank and Diane's trial
Buck Young as Assistant district attorney at Frank and Diane's trial
Colin Kenny as Spectator at Frank and Diane's trial
Bess Flowers as Shirley, attorney Barrett's secretary who greets arriving Diane
The film mostly receives positive reviews today. Dave Kehr from the Chicago Reader writes: "This intense Freudian melodrama by Otto Preminger (1953) is one of the forgotten masterworks of film noir... The film is a disturbingly cool, rational investigation of the terrors of sexuality...The sets, characters, and actions are extremely stylized, yet Preminger's moving camera gives them a frightening unity and fluidity, tracing a straight, clean line to a cliff top for one of the most audacious endings in film history."
Film critic Paul Brenner wrote, "Preminger transforms a second rate James M. Cain murder plot, re-orchestrating this textbook tale of passion and murder into a haunting and haunted refrain. The by then clichéd story line is pared away and brought down to an elemental level -- there is not a wasted scene in the film — and the story's familiarity breeds an aftertaste of inevitability and doom. The hallucinogenic nature of the proceedings is accented with Preminger's direction and camerawork, having actors drift from foreground to background or having the camera track to fluid and suffocating close-ups. Preminger, ever the mesmerizer, weaves his style into a half-dreamt haze of nightmare."
It was also named by critic Robin Wood as one of his top 10 films, shortly before his death.
In 1963, Jean-Luc Godard named it the 8th best American Sound film.