Twelve-year-old Teacup has never felt like she belonged anywhere—not in foster homes, not at school, and not imprisoned on the magical estate of the sorcerer Mr. Mason. Teacup, however, is not like Mr. Mason's other child prisoners—her fingernail clippings turn to copper, her hair makes people sick, and she can open magical portals. When Mr. Mason offers to make Teacup his apprentice, she accepts.
Life on Mr. Mason's estate is full of surprising wonders, from golden pigs who only eat the finest oatmeal to magical trays that can carry infinite weight. But there is great danger as well: Teacup and the rest of Mason's prisoners must compete every week in a murderous raffle that always ends in a child's death. Even though she's Mason's apprentice, Teacup is far from safe.
As Teacup learns more about sorcery, she realizes she has an important choice to make: Do her loyalties lie with the other children trapped by Mr. Mason, or with the deadly sorcerers who recognize her true potential? Can she turn her magic against Mr. Mason to save her friends, or will she become as wicked as him?