The Gorch brothers - who were a couple of lunatic hellraisers in the WIld West before they were turned into vampires - have arrived in Sunnydale. Buffy is busy helping Giles research them, and so misses health class, wherein the students are broken in pairs and given the responsibility of eggs to care for as if they were children. Buffy having been absent, gets to be a singly mother to 'Eggbert'.
however, these are not ordinary eggs, but the offspring of a bezoar that lives under school and has now come to life. The offspring bond to human hosts, and several students and adults - including Willow, Cordelia, Giles and Joyce - become drones for the bezoar. Only Buffy, who slayers the offspring before it can bond with her - and Xander, who hard-boiled his child - escaped unharmed. of course, Buffy's attempts to stop the bezoar are hindered by the Gorch brother deciding to attack.