A heartracing thriller from the New York Times bestselling author of NERVE Aislyn suffers from crippling shyness that is, until she s offered a dose of Charisma, an underground gene therapy drug guaranteed to make her shine. The effects are instant. She s charming, vivacious, and popular. But strangely, so are some other kids she knows. The media goes into a frenzy when the disease turns contagious, and then deadly, and the doctor who gave it to them...