Senior year at all-girl's Catholic school St. Joan's Academy has just begun, and Colleen Rowley and her friends are feeling the heat. Applications to Harvard, the battle for valedictorian, the high expectations of their parents, meeting boys in Cambridge . . . all of it has turned school into a pressure cooker.

When beautiful, popular Clara Rutherford starts having loud and uncontrollable tics while her horrified classmates look on, chaos sets in as more and more girls begin reporting bizarre symptoms: losing hair, body vibration, seizures...And then one of Colleen's best friends, Anjali, starts coughing up pins. The media quickly descends on the small town of Danvers, MA, as school officials, angry parents and the board of health scramble to figure out what's going on before it gets worse. Theories range from a latent Strep virus to environmental pollution, all to no avail. But as Colleen soon realizes, there's one thing nobody has factored in-Danvers, MA was once called Salem Village, the site of a similarly bizarre epidemic among teenage girls over 300 years earlier...