As a female Preying Mantis demon, ‘Natalie’ must find a virgin to copulate with in order to fertilise her eggs. To this end she takes on the name of a retired substitute teacher, Natalie French, and finds her way to Sunnydale High School, where vrigins abound a plenty. Murdering the nice biology teacher, Dr. Gregory, she takes his place, in her human form of course, and uses her powerful pheromones to attract the young male virgins in her class, starting with Blayne and Xander. Luring them to her house under the pretense of an after-school activity, she captures them and is about to mate with Xander when Buffy comes to the rescue. The She-Mantis is finally defeated by tactical use of a bat sonar recording (which the preying mantis cannot stand) and a big axe.