In an exchange of letters between scientist Alan and his wife Anne, it is discovered that there has been an increase in men killing women. Alan is in Colombia researching bugs, and Anne is in the United States. As these murders increase, scientists become more and more desperate to understand why this phenomenon is occurring. However, what becomes even more bizarre is that women, when attacked by these men, don't resist.

The media at first attempts to cover up this phenomenon, and many people suspect it is misogyny. However, Alan's fellow scientist friend, Barney, reveals that it is something more and that some virus is causing men who become sexually attracted to a woman to kill them. In addition, this virus causes a woman who is sexually attracted to a man to become submissive when being killed.

Alan decides to return home, but when he arrives in America, he begins to develop sexual urges for his daughter, which he fears are violent. Alan, afraid that he will kill his daughter, isolates himself from his family in his lab. Anne and his daughter are confused, but Anne tries her best to stop her daughter from seeing her dad. Sadly, the daughter sneaks into Alan's lab, and he kills her.

The infection keeps spreading, and more and more men begin killing women. Anne, desperate to survive, now travels alone in fear for her life. The female population is dying out, causing men to kill the boys. Anne contemplates her life and wonders how the world came to this. One day, she's in the woods and sees a beam of light that looks like an angel. She claims that these beings or aliens created this virus to destroy the human race.