Yan Dan is the sole descendant of the ancient tribe the Four-Leaved Scorpion. Yan Dan’s entire being is a treasure trove of medicines. She and twin sister Zhi Xi transformed into human form a century before while attending the Queen Mother's Feast, but Yan Dan faced the greatest trial of her life - the love trial. Falling in love with Lord Ying Yuan resulted in her wasting the following 800 years forgetting him. Such a high price to pay! Now the supportive Yu Mo enters her life, encouraging her daily to perform good deeds. While punishing evil, they encounter Lord Ying Yuan's current reincarnation, Tang Zhou, the demon hunter. They assist Tang Zhou in his quest to locate the four ancient artifacts, uncovering an even more mysterious secret. Can the trio find the evidence they need despite the dangers?