Nancy is determined to prove she’s not crazy and has Harry drive her through the desert in search of the spacecraft. They find the alien craft, but when the alien shows up Harry abandons Nancy, leaving her to the mercy of the space creature. As the extraterrestrial takes Nancy’s diamond necklace it accidentally scratches her, exposing her to dangerous levels of radiation. Harry plans to put her out of her misery so he can inherit her father’s money, but within hours Nancy begins to grow to enormous proportions and soon she can’t be contained by doctors or law enforcement. In all her fifty-foot fury, she tracks down her husband and his mistress in a bar. She then proceeds to squash the other woman with a support beam and abducts Harry. The sheriff puts a stop to Nancy’s shenanigans and fires at an electrical transformer nearby, electrocuting both Nancy and her husband to death.
Nancy seeks out psychiatrist Dr. Theodora Cushing for help with her repressed anger, but things come to a head when she discovers her husband and another woman together in a motel room. Like the original Nancy, she decides to hit the road in her car but encounters aliens and is zapped by gamma rays. Nancy’s anger then begins to manifest itself as physical growth and soon she is fifty feet tall, tearing apart the city looking for her unfaithful husband. Her reign of terror finally ends when Nancy is backed into power lines by an encroaching helicopter.
An interesting difference between the portrayals of the fifty foot woman by Allison Hayes and Daryl Hanna is in how they deal with the other woman. Hayes squashes her competition like a bug no questions asked, but when Hanna confronts her rival, instead of killing her she gives her a speech on female empowerment. Grasping a screaming Honey in her left hand, Nancy looks her in the eye and says “Don’t be stupid your whole damn life. You’re better than they are. You’re smarter than they are. And you know more than you think. We all do.” Hanna redirects a woman’s rage at infidelity (personified with her physical growth) not at the mistress, but at the man as the true source betrayal.