This is the story of seventeen-year-old Prenna James, who immigrated to New York when she was twelve. Except Prenna didn't come from a different country. She came from a different time - a future where a mosquito-borne illness has mutated into a pandemic, killing millions and leaving the world in ruins. Prenna and the others who escaped to the present day must follow a strict set of rules: never reveal where they're from, never interfere with history, and never, ever be intimate with anyone outside their community. Prenna does as she's told, believing she can help prevent the plague that will one day ravage the earth. But everything changes when Prenna falls for Ethan Jarves.