Prince Cho Yihyeon is forced to remain in the imperial palace of a foreign land for three long years. The emperor awaiting him, Tae Won, is rumored to be a merciless despot, yet he greets Yihyeon with unexpected innocence and charm. But that gentleness doesn’t last. Beneath the smile lies obsession, and Tae Won’s growing fixation leaves Yihyeon frightened and confused. Separated from his family and slowly losing himself, Yihyeon begins to fade.

Can love - or survival - exist under an emperor’s twisted devotion, in a palace swallowed by a moonless night?