When Yu Seo-Hyeon sacrificed her life to save her first love, Ciel de Leopart, she never expected to wake up as Irene de Closhe in a world straight out of a book. Amidst this bizarre twist, she reunites with Ciel, who has now become a supporting male lead destined to betray the crown prince. As her unique guide abilities resurface, Seo-Hyeon is haunted by Ciel's intense, madness-filled gaze, a stark contrast to the man she once knew. Tangled in a web of past love and new identities, Seo-Hyeon must navigate a treacherous path where past and present collide.