Lee Eun keeps a close eye on Deok Su, who possesses the golden key, waiting for the right moment, while Deok Su grows more cautious, noticing Eun's suspicious looks. Meanwhile, a murder case involving a fake Hongpae shakes Yongcheonru, raising the tension even higher.

Amidst suspicions about their identities, Eun-ho and Deok-su develop confusing feelings for each other. Meanwhile, Jun-hwa uncovers a great secret.