After the adventures in the Seven Star Palace and the underwater Xisha Tomb, Wu Xie returns home to Hangzhou. He gets a call from Lao Yang who tells him of an adventure in the Qinling mountains and invites Wu Xie to join him in going back. All the while, Zhang Qiling is secretly helping Wu Xie. More info here: https://daomu-biji.fandom.com/wiki/Buried_Tree_Devil