An immortal cat god, four hundred years after the death of its first master - the emperor, once again came to its former home - the Forbidden City, where it met the bureau cat and other wild cats, learned about their lives, also witnessed the transformation of the former Imperial Palace into the National Palace Museum and the relocation of the Forbidden City relics to the south. At the end of the story, it decided to stay in the Forbidden City and guard this ancient palace forever. This is a story about the cats and people of the Forbidden City, full of warmth and love.