It's late summer 1793, and the streets of Philadelphia are abuzz with mosquitoes and rumors of fever. Down near the docks, many have taken ill, and the fatalities are mounting. Now they include Polly, the serving girl at the Cook Coffeehouse. But fourteen-year-old Mattie Cook doesn't get a moment to mourn the passing of her childhood playmate. New customers have overrun her family's coffee shop, located far from the mosquito-infested river, and Mattie's concerns of fever are all but overshadowed by dreams of growing her family's small business into a thriving enterprise. But when the fever begins to strike closer to home, Mattie's struggle to build a new life must give way to a new fight—the fight to stay alive.