Su Hongjin, a modern female forensic doctor, accidentally traveled to the Yan Dynasty in another world during a mission.
When the former prince Yu Zhuoli became anonymous and fell into the streets when the country was destroyed, he and the time-travelling Su Hongjin made a living by stealing.
When she was fifteen years old, Su Hongjin was selected as a spy by Yu Zhuoli without knowing it, and was arranged to go to Prince Yirui's palace to steal intelligence.
In the palace, she accidentally met Xia Zhiyi, a woman who also came from modern times.
Su Hongjin is delicate and cautious, and she only wants to rescue her childhood sweetheart.
Xia Zhiyi, on the other hand, has avant-garde concepts and an open mind, and likes to make friends with different men.
There are intrigues in the palace, and the chaos in the court...
The mystery gradually unravels and the truth gradually becomes clear. Su Hongjin discovers that everything is a scam and that she has been used all along.
He cherished her, loved her, and protected her; but she lied to him, hurt him, and harmed him...
After all the mechanisms have been exhausted, what is finally achieved, is the two people happy or resentful?