Martha Beck, an overweight nurse living with her overbearing mother, becomes emotionally invested in a lonely hearts club to find companionship. She meets Raymond Fernandez, a smooth-talking con man who seduces women to steal their money. Despite his dishonesty, Martha falls deeply in love with Raymond and the two embark on a passionate relationship. Determined to keep him, Martha joins Raymond's schemes and begins accompanying him as he defrauds lonely women across the United States. Their partnership evolves into mutual dependency, driven by love, jealousy, and a shared willingness to exploit vulnerable individuals.

To further their deception, Raymond poses as Martha's brother while they con their victims, blending into various households and promising marriage to desperate women to gain their trust and access their financial resources. As the duo dives deeper into crime, their crimes escalate from fraud to murder. The couple's thrilling journey is peppered with instances of intense psychological manipulation, deceit, and violence. Driven by insatiable greed and desperation to maintain their toxic bond, their crimes increasingly draw the attention of law enforcement, leading to a spiral of catastrophic events that threaten to upend their lives permanently.