An unforgettable epic romantic thriller about a girl from the future who might be able to save the world . . . if she lets go of the one thing she’s found to hold on to.Follow the rules. Remember what happened. Never fall in love. 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.