Her real name is never revealed, as "Milly" is used in order to protect her true identity.
One day, staying hidden in the shadows, "Milly" catches a man named Gail Meiklett fighting with his girlfriend, Carol Ardshiel. She anonymously sends the man a video tape in the mail, which he receives and views. "Milly" appears on the screen, referring to Gail by name, as well as Carol, whom she belittles. She then proceeds to some erotic dirty talk before the recorded footage upbruptly ends.
Finding it very bizarre, Gail decides to show the video to Carol, who stops by shortly after receiving a note (forged by "Milly") which states that she was to come over for an urgent matter. The first couple minutes of the footage begin the same as before, only this time the villainess follows up on her words by removing her clothes and masturbating as she speaks. The two are even more shocked when Gail appears on the screen as well and engages in oral intercourse with "Milly". Feeling that all he wanted was to show her some crude, homemade sex tape, an enraged Carol storms out of his apartment in a huff.
A little while later, "Milly" herself decides to pay a visit to Gail, with the intention of "making a deal" with him. She explains that the video tape that she sent him was no ordinary one; that it can record the thoughts of the viewer, and then display them on screen the next time the tape is played. She goes on to say that the project is being developed and marketed as a new type of "video game" and wishes for Gail to invest money in it. Due to the woman's tricks up until that point, he rejects, stating that the video and her false note caused a big rift between he and his girlfriend. However, when she displays for him the violent thoughts that were going through Carol's mind due to her anger, she invites him to use the invention to achieve the same release for himself.
Gail is at first resistant, but with "Milly's" strong encouragement, he eventually begins to fantasize himself violently taking out all of his frustrations on Carol, while simultaneously watching as it comes alive on the screen. After coming to his senses, Gail is embarrassed by what he had just done, but agrees to invest. Upon leaving his apartment, however, the woman makes her way to the nearest phone both and dials the police.
The next morning, "Milly" contacts Gail and tells him to turn on the local news. He does, and is horrified to see that Carol was actually murdered the night before. The woman then divulges that, at the time he had recorded his fantasies, the video tape had been set to a special mode, which allows it to directly and physically affect the target of the receiver's thoughts. In other words, when Gail was brutalizing Carol in his imagination, a recreation of himself was doing the same to the real person, which ended up killing her.
"Milly" goes on to say that she was once a private secretary to an unnamed inventor. After developing the amazing video tape technology, the brilliant man felt that he had to destroy it, for he had not realized what a deadly weapon it could turn into during its creation. Appalled that he would put ethics over profit, combined with her failed attempts to persuade him otherwise, "Milly" then murdered him, stole the invention for herself, and has been using it to blackmail random men ever since. The final nail for Gail is that, because the fantasy was also recorded on the tape, she is in possession of "video proof of his crime". She demands that he give her $5,000 dollars every month, or she goes straight to the authorities.Scared and devastated, Gail struggles to see in what possible way he could escape this nightmare. He eventually decides that his only chance is to locate another one of "Milly's" tapes - one that was given to another potential blackmail victim - and pilfer it. After months and months, he finally succeeds. Gail then ambushes a stunned "Milly" and once again indulges in a violent fantasy; one that deals a very gruesome end to the one who sought to manipulate him.