The She Mantis (Musetta Vander) infiltrates Sunnydale High by killing Buffy's favourite teacher, Dr Gregory, whose decapitated body is found in the school canteen refrigerator. The shape-shifting, insect-like She Mantis then gets his job by assuming human form (as a beautiful young woman) and the identity of a substitute teacher, Natalie French.
Quickly winning over the male students including Xander, she soon has candidates lining up to become her mate, who are unaware that they'll die in the process. However Buffy, who has seen her head rotate round in a "full-on Exorcist twist", is highly suspicious and rushes to the rescue...
