Twelve-year-old Chili Sue Mahoney has never been outside of her small Appalachian town. Mercy Hill, Kentucky, is home, with its meadows full of flowers, nights full of fireflies, grand mountains surrounding her little town. But it's also a place of poverty and old ways, and Chili longs to see the world.

So she's thrilled when the mysterious, world-traveled Miss Matlock returns to Mercy Hill—amidst whispered rumors—and becomes the seventh-grade substitute teacher. As Chili and her classmate Willie Bright spend time with Miss Matlock, listening to her stories of faraway lands, Chili discovers that there may be more to Mercy Hill than she thought: beauty, in the people and places she's known all her life, and deep-rooted secrets, sometimes where they're least expected.