The stuck-up attitude of Cordelia (Charisma Carpenter) comes back to hurt her in this important first-year episode. While campaigning to be crowned Sunnydale High's May Queen, Cordelia's date is clubbed to death by a possessed baseball bat. A friend of Cordelia's then falls down some stairs, leading Buffy to believe that an invisible assailant might be at work in Sunnydale. Soon enough, Buffy discovers evidence of a girl named Marcia Ross (Clea DuVall) living in the recesses of Sunnydale High. Among her belongings, she finds a yearbook signed by Xander (Nicholas Brendon) and Willow (Alyson Hannigan), although no one seems to remember the girl. Treated as invisible for so long, Marcia has actually become invisible and is exacting revenge upon her classmates. Buffy finds a way of stopping her before she can kill Cordelia, creating some goodwill between the two. By the end, Marcia is taken away by federal agents to be rehabilitated at a school for other invisible students, foreshadowing other political entanglements Buffy will encounter in future seasons. Another point of interest in this episode is the first meeting between Angel (David Boreanaz) and Giles (Anthony Stewart Head). ~ Matt Collar, Rovi