Chasing the Murderer in the Rain

When the parents returned home, the child had disappeared. They searched every corner but could not find the whereabouts of the child. In order to save his beloved son, the father embarked on a difficult and bloody road of atonement, while the mother did not hesitate to fall into prostitution to pursue clues. A mysterious dragon roars from underground, a dragon demon appears in the middle of the river, and hundreds of thousands of red carp corpses float down in the torrent... What is the truth behind all these mysteries? For more original reasoning, please join the Yujing Reading Group Q210121411.