The Fever by Megan Abbott

In this impossible-to-put-down "panic attack of a novel," a small-town high school becomes the breeding ground for a mysterious illness.

Deenie Nash is a diligent student with a close-knit family; her brother Eli is a hockey star, and her father is a popular teacher. But when Deenie's best friend is struck by a terrifying, unexplained seizure in class, the Nashes' seeming stability dissolves into chaos. As rumors of a hazardous outbreak spread through school, and hysteria and contagion swell, a series of tightly held secrets emerges, threatening to unravel friendships, families, and the town's fragile sense of security.

The Fever is a chilling story about guilt, lies, and the lethal power of desire.