In 2005, at a second-hand market along the Yangtze River, Shen Yan, a descendant of corpse collectors, accidentally obtained a bronze keel fish lamp - an ancient lamp that lit up with blood and was associated with family secrets. It not only revealed his grandfather's strange prophecy before his death that "the water veins would open and half of the south would be flooded", but also led him to the truth behind his father Shen Shanhe's disappearance in 2000.
In order to find his father, Shen Yan took the fish lantern to the Laoye Temple in Poyang Lake and met Lin Xi, the descendant of Mu Xing's tomb keeper. The two crossed the gloomy underground river and faced the "water ghost" controlled by the soul-spinning algae and the water-suppressing beast that could swallow the entire ship. They gradually learned about the secrets hidden in the Yangtze River Basin for thousands of years: the five major families of metal, wood, water, fire, and earth have guarded the "water vein gate" at the bottom of the river for generations to suppress the remnants of the ancient water demon Gong Gong. Their father was trapped deep in the underground river while trying to strengthen the loose tomb door.
As the exploration progressed, Shen Yan and Lin Xi met Jin Shuo, the genius of the Jin element, Chu Yao, the earth element perceiver, and Yan Lie, the fire flame controller. The five formed a tomb guarding team and embarked on a journey to collect the "Five Elements Secret Spectrum". They broke into the Dongting Cave, explored the Three Gorges Huoling Cave, and fought against the Golden Palace Reef of the Yangtze River. They not only had to crack the trap of ancient institutions and resist the "Fanjianghui", a tomb-robber organization specializing in seizing the Poseidon Needle, but they also had to face the curse and knot inherited by the family - Shen Yan needed to accept the fate of "the Shen family was born to block the water vein gate", Lin Xi needed to solve the mystery of his mother trapped in the underground river, and Yan Lie needed to let go of his obsession with the family's injustice.
