In letters to her friend Leo who left for school on the mainland, Kaelyn describes a strange illness moving through her island community. It starts with a fever, then itching, then manic behavior. Even though her father works at the hospital, they don't know how to cure it, and no one is safe. As more fall ill and die and the island is quarantined, Kaelyn has to join forces with people she never would have called friends before.

This is a book I had requested as an ARC from Netgalley back in 2012, and reading a plague novel now, after we've all lived through COVID, was surreal. The island setting narrowed down how easily they could lose internet and power, and how small groups on the island might rebel. Since the letters to Leo were never mailed out, this seemed like a strange plot device rather than a diary. I'm assuming Leo may become a bigger character in the sequels - and I'd hope we'd also get more information about the mainland. The climax only made me feel sad and we didn't get to know the "bad guys" - a gang on the island that tries to intercept the food supply - enough to see them as more than a faceless antagonist. Still, if you enjoy stories about survival in a post-apocalyptic setting, there's enough survival tips and action to keep the story moving.