People all over the world say that Chang'an is a prosperous place with endless wind and moonlight. But only those trapped within the red wall know that every step of this Zhumen Palace is based on human hearts and calculations, and every step is startling and chilling. The heroine was originally a spectator reading the history books thousands of years later, and clearly recorded all the endings of the last years of Kaiyuan: the prince was deposed, the six kings were imprisoned, the three kings ascended to the Nine Five-Year Plan, and the nine kings wandered for the rest of their lives. She traveled back in time with a whole history book full of joys and sorrows. She originally thought she could be alone and avoid all the blood, tears and regrets. But later I realized that history will never be rewritten based on the selfishness of an outsider. She could clearly see their doomed fate, but she was still moved and got involved.