Three years ago, Qu Heng asked the late emperor to marry Fang Yunxi, whom he had been in love with for many years, but what he got was an imperial decree to marry someone else. When the late emperor passed away, he gave Qu Heng a key with a spotted dragon pattern, but he didn't know what it was for. Keys, secrets, and the truth about their father's death made the two reunited three years later decide to look for clues together to unlock the secret. But at this time, His Majesty, Qu Heng's brother wants to marry Fang Yunxi as his concubine. Will Fang Yunxi, who has successfully escaped, return to the palace again for the truth, and what should Qu Heng do? What should Qu Heng's current wife do? How to resolve this complicated relationship...
Philosophy: There are more and more clues, and the truth is getting bigger and bigger. Can the reunited lovers overcome all difficulties to uncover the truth, and can they be together?