Her widowed mother, sister, and Lily move in with their Korean grandmother, Halmoni. As Halmoni's health declines a tiger arrives offering Lily the opportunity to heal her grandmother. She must retrieve what Halmoni stole long ago. As Lily searches, she discovers her family's heritage, a world of folklore, magic, and secrets. As she gets closer to finding her mother's hidden secret, Lily begins to distrust the tiger. Can Lily save her grandmother?