Martha Beck is a sullen, overweight nursing administrator living in
Mobile, Alabama, with her elderly mother. Martha's friend Bunny surreptitiously submits Martha's name to a "lonely hearts" club, which results in a letter from Raymond Fernandez of
New York City. Overcoming her initial reluctance, Martha corresponds with Ray and becomes attracted to him. He visits Martha in Alabama and seduces her. Thereafter, having secured a loan from her, Ray sends Martha a
Dear Jane letter, and Martha enlists Bunny's aid to call him with the (false) news that she has attempted suicide. Ray allows Martha to visit him in New York, where he reveals he is a
con man who makes his living by seducing and then swindling lonely women. Martha is unswayed by this revelation. At Ray's directive, and so she can live with him, Martha puts her mother in a nursing home. Martha's embittered mother disowns her for abandoning her. Martha insists on accompanying Ray at his "work." Woman after woman accepts the attentions of this suitor who goes courting while always within sight of his "sister". Ray promises Martha he will never sleep with any of the other women but complicates his promise by marrying pregnant Myrtle Young. After Young aggressively attempts to bed the bridegroom, Martha gives her a large dose of pills, and Ray puts the drugged woman on a bus. Her death thereafter escapes immediate suspicion. The swindlers move on to their next target, and after catching Ray becoming intimate with the woman, Martha attempts to drown herself. To placate her, Ray rents a house in
Valley Stream, a suburb of New York City. He becomes engaged to the elderly Janet Fay of
Albany, and takes her to the house he shares with Martha. Janet gives Ray checks for $10,000 but then becomes suspicious of the two. When Janet tries to contact her family, Martha bludgeons her with a hammer before she and Ray strangle her. They bury her body beneath their cellar floor in her trunk, tossing into the grave the two framed depictions of Jesus that, Martha notes sarcastically, she'd told them she took everywhere she went. Next, they spend several weeks living in
Michigan with the widowed Delphine Downing and her young daughter. Delphine, younger and prettier than most of Ray's conquests, confides in Martha, hoping that she will help her persuade Ray to marry her as soon as possible because she is pregnant with Ray's child. Martha is in the midst of drugging and smothering Delphine when the woman's daughter enters the room with Ray. He shoots Delphine in the head, and Martha drowns the daughter in the cellar. Ray tells Martha that he has to move on to one more woman, this one in
New Orleans, and then he will marry Martha; he repeats his promise never to have sex with any of his marks. Realizing that Ray will never stop lying to her, Martha calls the police and waits calmly for them to arrive. The
epilogue takes place four months later, with Martha and Ray in jail. As she leaves the cellblock for the first day of their trial, Martha receives a letter from Ray in which he tells her that, despite everything, she is the only woman he ever loved. On-screen titles state that Martha and Raymond were electrocuted at
Sing Sing on March 8, 1951. ==Cast==