Suffering from a chronic "nightmare disorder," police officer Lu Yi has spent years secretly investigating the truth behind her father's mysterious coma. Her path crosses with Lin Shen, a cold and aloof female detective, and the two join forces to solve a series of bizarre homicides. As their bond deepens, Lu Yi begins to uncover unsettling clues. There are hints that Lin Shen may be inextricably linked to her father's long-buried case...