During his late-night shift at a San Francisco hospital, Dr. Jeff Cameron is called to attend a beautiful, unidentified woman who has attempted suicide. When the woman finally comes to, she sees the white rose that Jeff had ordered for his fiancée, nurse Julie Dorn, and assumes it is for her. Later, Jeff learns that the woman, Margo, discharged herself after giving a phony last name, but has wired him to come see her that night. At her seacliff home, Margo tells the concerned Jeff that she attempted suicide because she was feeling lonely after the death of her mother. Margo also states that her father, Frederick Lannington, is in Canada and that, because of his social position, she fears scandalous publicity. Attracted to his seductive patient, Jeff agrees not to notify the police about her suicide attempt and breaks a date with Julie. After a brief but intense courtship, Jeff and Margo find themselves deeply in love, but Margo shocks Jeff one evening when she announces that she is soon leaving for Nassau with her disapproving father. Although Margo promises Jeff she will try to change her father's mind, Jeff becomes anxious and goes to confront Lannington at his house. There, he is stunned to learn that the middle-aged Lannington is not Margo's father, but her husband. Lannington also reveals that Jeff is not Margo's first lover and alludes to the difficulties he has had living with his unloving wife. Disgusted by Margo's deceit, Jeff walks out of the house, but rushes back when he hears her screaming. Seeing Margo's bloodied ear, Jeff is about to take her away when an enraged Lannington starts to beat him over the head with a poker. After Jeff knocks the crazed Lannington out, he goes to the bathroom to tend to his wounds. The woosy Jeff then discovers that Lannington is dead, and although his first impulse is to call the police, Margo convinces him to flee with her to Nassau. At the airport, however, the couple see two policemen talking to the ticket agent and leave in a panic. While driving toward Mexico, the still dazed Jeff realizes that he has suffered a concussion and tells Margo that he will probably fall into a coma within forty-eight hours. Later, after trading Margo's expensive convertible for a rundown truck, Jeff crashes into a truck in an Arizona desert town. Anxious to depart undetected, Jeff uses most of his cash to bribe the drunken driver, and the couple speeds out of town just as radio reports announce Lannington's murder. That night, they are detained in Postville, another Arizona town, for violating the rules of "Whiskers Week," a celebration in which everyone must sport beards and dress in western costumes. Faced with a twenty-five dollar fine, Margo tells the intoxicated townsmen that she and Jeff are planning to marry. The townspeople then insist that the couple "get hitched" that night and cajole them into staying in town. In their "honeymoon suite," Margo, who has been preventing Jeff from listening to the radio, secretly listens to it herself and becomes angry when the announcer mentions the psychiatric treatment she underwent. Later, after Margo and Jeff have fled town, the sheriff realizes who the newlyweds are and notifies the border patrol, who inform him that Lannington was smothered to death. To avoid the border patrol, Margo pawns an expensive bracelet and buys illegal transportation into Mexico. While waiting in a cheap hotel for their van, Margo reveals to Jeff, whose hand and side have become numb from a progressive paralysis, that for years she has been stashing Lannington's money in a Mexico bank. Shocked by this confession, Jeff tells Margo that he cannot go to Mexico with her. Margo rails against Jeff, who finally deduces her insanity and tells her that he has only pity for her. An enraged Margo smothers the now-unconscious Jeff with a pillow and then boards the Mexico-bound van. When Margo sees Jeff staggering toward the stopped van, she shoots him in a terrified rage and is then shot by the border police. Before she dies, Margo proudly confesses to her husband's murder. Later, in a hospital, a recovering Jeff is about to send a white rose to Julie when she appears at his bedside.