Lin Miaoyun, a modern history PhD, accidentally transmigrates to 1402 and becomes Xu Miaoyun, Empress of the Yongle Emperor Zhu Di. To her surprise, Zhu Di can hear her thoughts. During the coronation ceremony, he hears her complain about how heavy the phoenix crown is and is stunned. As her memories merge, she brings her modern outlook with her, sympathizes with the former officials of the Jianwen Emperor, and tries to save Empress Ma with modern medicine, but fails. Her thoughts also lead Zhu Di to prepare defenses for Beiping ahead of time.
During the Jingnan Campaign, she uses a "divine revelation" to improve gunpowder and aid the war effort. She compiles the Instructions for the Inner Quarters to spread ideas of equality, but is impeached. When she is struck by an arrow while saving Zhu Gaochi and lies near death, she reveals the truth about her transmigration. Zhu Di both relies on her and suspects her, yet his deep devotion shows through when she is in danger.
While governing, she pushes for the establishment of schools for girls and persuades Zhu Di to abandon the burning of books and lavish rewards for his maternal relatives. However, her modern memories gradually fade, while Zhu Di faces the loss of his ability to hear her thoughts. On the eve of the northern campaign, she offers her life in a sacrifice to Heaven to ensure Zhu Di's safety. Zhu Di vows never to take another empress.
A thousand years later, a modern archaeological team discovers two coffins in the Changling Mausoleum. Lin Miaoyun weeps at Zhu Di's portrait in a museum, and his promise, "I'll transmigrate to find you," echoes in her ears, completing the circle across time and space.
I lost my temper even before I watched it.