She is never cold, she always knows exactly what time it is, and her hair grows two inches while she sleeps. Fifteen-year-old Corinna Stonewall--the only Folk Keeper in the city of Rhysbridge — sits hour after hour with the Folk in the dark, chilly cellar, "drawing off their anger as a lightning rod draws off lightning." The Folk are the fierce, wet-mouthed, cave-dwelling gremlins who sour milk, rot cabbage, and make farm animals sick. Still, they are no match for the steely, hard-hearted, vengeful orphan Corinna who prides herself in her job of feeding, distracting, and otherwise pacifying these furious, ravenous creatures. The Folk Keeper has power and independence, and that's the way she likes it.