Set in the Republic of China era, the story follows Guo Deyou, a young man known as the 'River God' who possesses a unique ability to see visions when he comes into contact with water. Alongside his friend Ding Mao, the son of a wealthy businessman who returned from studying forensic science abroad, they investigate a series of bizarre and supernatural occurrences plaguing the city of Tientsin. The duo must navigate a web of ancient cults, political corruption, and dark folklore to protect the city from impending doom. As the mystery deepens, they are joined by Gu Ying, a spirited girl with a deep knowledge of folk traditions, and Xiao Lanlan, a reporter seeking the truth behind the city's secrets. Together, they confront a shadowy organization known as the Demon Cult, which seeks to unleash a catastrophic ritual. The series blends historical drama, investigative mystery, and supernatural elements, highlighting the clash between traditional superstition and modern scientific reasoning in a rapidly changing society.