Su Nian, a female doctor of modern criminal investigation psychology, transformed into the legitimate daughter of the prime minister who was poisoned. The original owner appears to be cowardly, but is actually a thorn in the side of the prince. She was assassinated by the regent Xiao Yan as soon as she woke up. After killing the assassin, she was wanted by him for being a "witch who deceived the public". Su Nian used "knowing the secret of the late emperor's edict" as a bargaining chip to actively negotiate, turning from a mortal enemy into an ally, and jointly uncovered the seventh prince's conspiracy to seize the throne. However, she discovered that the original owner was rescued by Xiao Yan when he was young, and the "old friend" Xiao Yan had been looking for for many years was herself. When Xiao Yan was falsely accused of treason, she was willing to enter the palace as a hostage; when she was in a desperate situation, he led his troops to crush the palace gate. In the end, the truth was revealed, but she chose to leave the palace and open a school with modern knowledge. Under the machinations, love and hate intertwined. He changed from a cold and powerful minister to someone who was willing to lay down his country for her. She went from just wanting to live to being willing to die for him.
