The original idea for this novel came from a question asked by someone in Zhihu: if you were writing a plot for Assassin's Creed, where would you put it in the background?

Assassin's Creed is a sandbox video game where the protagonist travels through an ancient or modern city to carry out various assassination missions, which I really enjoy.

When I saw this question, the first thing that came to mind was Chang'an City in the Tang Dynasty.

Chang'an City in the Tang Dynasty was a dream place for me. This is a great city with orderly and magnificent momentum, where people of all colors gather in the three religions and nine streams, and the romantic style and prestige are criss-crossed, the life is prosperous and colorful, and the atmosphere is open and diverse. There, anything can happen, and it's really the most suitable stage that a creator can think of.

Imagine the figure of an assassin jumping down the Big Wild Goose Pagoda under the full moon, and the flaming red lantern that pursues him stretches from Suzaku Street to Qujiang Pond, startling countless resident birds in the Leyou Plain...... It's a fragment full of imagery, entangled with mystery and grandeur at the same time, and what a fun thing it would be if it could be written.

So I wrote a few thousand words by hand, at first I simply wanted to open my mind, but the more I wrote, the more excited I became, and a long story took shape quietly. As the story progressed, my ambitions swelled. I tried to make it faster-paced, more sophisticated and complex in the story, and more so that the characteristics of each character were closer to what modern people perceive. To put it bluntly, what I wanted to present was no longer a costume assassin adventure, but a modern story that took place in a cosmopolitan city, except that it happened to take place in ancient times.

Fortunately, Chang'an is such a city with a temperament that transcends time and space, and it can accommodate both classical and modern elements without making people feel out of place. So this story has gradually changed from a slow costume legendary martial arts drama to a fast-paced lonely hero drama with an ancient anti-terrorism theme. In order to make this trait more obvious, I also re-cut the plot, just like the episode method of the American drama "24 Hours", every half hour is a chapter, a total of 24 chapters, exactly one day.

The biggest challenge in writing such a work is not the weaving of the story and the shaping of the characters, but the accurate description of the details of life in that era. In order for readers to be immersed in the scene and truly feel a living Chang'an City, the author must know that period of history well: how to drink tea, how to eat, where to go to the toilet, how to ride the car, what women wear when they go out, how men spend money when they go out, up to the imperial court rules and regulations, down to the price of food, and even what direction the sewers in Chang'an City are, what is the shape of the railing that separates the water, and so on - what is to be depicted is actually a whole world, no matter how detailed the writing is, it is not too much.

For this reason, I looked up a lot of materials, read a lot of monographs and archaeological reports, and went to Xi'an several times for field trips, hoping to get closer to the real Chang'an City.

Here, I would like to thank Mr. Yu Gengzhe, Jinghong, Sweeping Meow, Forest Deer, Black Belly Little Hoof and other friends for their strong support, they provided me with a lot of precious information, and also took the time to read the clumsy work carefully, and gave various text and plot opinions. I have always been grateful for this intention. For an amateur lover of literature and history, it is great to meet such a knowledgeable and instructive friend.