I've put an Easter egg in the novel that readers who want to know more about it can try to find. The clue is a picture called "The Watson Family's Parrot in a Straw Hat" (It's 沃森家戴着草帽的鹦鹉 in Chinese), which I put on the Internet. Find it and you will see a series of binary numbers, crack it and you will get this Easter egg. And the password to crack it is hidden in the novel, it is a series of numbers, good luck.
Another note: Tales of City-state is a series of novels divided into three parts of approximately one million words. The “Tales of City-state: Time Travelers from the Umbrella House” is the first installment. The second installment, “Tales of City-state: Amandine's Cloak of Invisibility" has already been written, and the third installment, "Tales of City-state: Meiko and the Great Knight Masanami" is still being written, so stay tuned!