Jamie Hessen's life is far from ordinary. Diagnosed with narcolepsy with cataplexy when she was young, she has learned to handle life's many curveballs. Living in the small town of Banshee, where everyone knows everyone and life consists of hockey, boyfriends, and shopping, she has some stability.

As her senior year winds down, Jamie looks forward to the typical celebrations that graduation brings. But seemingly out of nowhere, a murder marks her high school as a place of terror, quenching any previous sense of solidarity.

When the first teacher is found dead, Jamie and her classmates are shaken. When the bodies begin to accumulate, normal becomes a thing of the past and Jamie's life is turned upside down as the town's secrets unfurl.

Ordinary small-town life just became interesting...