In a fictional near-future Korea, robots have integrated seamlessly into society. They are housekeepers and policemen, teachers and bus drivers. They are our lovers. They are even our children.

Siblings Jun and Morgan Cho haven't spoken to each other in several years. The children of a celebrated robot designer, both are still grieving the loss of their brother Yoyo, the earliest prototype for what humanoid robots have now become-nearly indistinguishable from the real thing. But Yoyo was always bound for a darker purpose, and his absence has left a chasm in the siblings' lives.

When a strange disappearance thrusts the siblings back together, neither of them realizes that the investigation will not only force them to confront their fractured family's past, but will also bring them back to Yoyo himself.

At once a thrilling page-turner and a heartfelt story of the ties between siblings, Luminous is an unforgettable literary debut.