Playful, ambitious, and exquisitely imagined, What Is Not Yours Is Not Yours is cleverly built around the idea of keys, literal and metaphorical. The key to a house, the key to a heart, the key to a secret—Oyeyemi’s keys not only unlock elements of her characters’ lives, they promise further labyrinths on the other side. In “Books and Roses” one special key opens a library, a garden, and clues to at least two lovers’ fates...