During the summer of 1793, Mattie Cook lives above the family coffee shop with her widowed mother and her grandfather. She spends her days avoiding chores and making plans to turn the family business into the finest Philadelphia has ever seen.

But then a yellow fever epidemic breaks out, devastating the city and threatening everything Mattie holds dear. As the cemeteries fill with fever victims, fear to turns to panic, and thousands flee the city. Then Mattie's mother falls ill, and insists that Mattie and her grandfather escape as well. But the fever is everywhere, and suddenly Mattie's struggle to build a better life must give way to something even more important—the fight to stay alive!