At the foothills of Yunmeng Mountain outside Qingzhou City, the autumn rain always brings with it an inexorable coolness. It hits the blue tiles of Tianji Academy, splashing fine water splashes, winding along the tile eaves, and forming a shallow pool in front of the steps. The pool of water reflects the faded wooden plaque at the entrance of the courtyard. The four official script characters "Tianji Academy" were written by Xie Jingxing himself. The writing is thick but has an edge, which is very similar to what he looks like now - a half-worn green cloth Confucian shirt with frayed cuffs. He is holding a dog-eared copy of "The Art of War" in his hand, standing under the cloister of the academy library, looking at the clouds and mist in the distance in a daze.