In 1969, Lydia and Abbie are best friends at an English girls school. Lydia, the neglected daughter of an agoraphobic mother, becomes fixated on Abbie, who has begun to explore her sexuality. After having sex with Lydia's brother Kenneth in an attempt to abort her pregnancy by another boy, Abbie begins to suffer from Mass psychogenic illness. She suffers an episode after a stint in detention with Lydia and dies in the process. Following Abbie's burial, Lydia begins suffering as well from fainting spells, and it soon becomes an epidemic, with numerous girls and a young teacher in the school spontaneously passing out for no more than a few seconds. Lydia becomes convinced that the administration must take action, much to the chagrin of the school principal.