(No System ✘ post-apocalypse ✘ merfolk ✘ virus ✘ venomous people)
The Di people wage revenge on humanity over severe ocean pollution.
Li Xin'an helps a person with disabilities and receives a clown doll for free. Little does he know that the doll carries a virus called Thousand-Day Blue.
This train bound for the ocean floor carries the ocean's hatred. The ocean sucks all the moisture from the land, while the virus invades and terrestrial life teeters on the brink of extinction.
When Li Xin'an wakes up, he finds the world unnaturally dim, everything before his eyes like a vision of hell. Dust swirls in the air, birds circle in flocks, and the masses of people outside the train leap into the lake of their own accord.
Li Xin'an is a descendant of the blue-blooded nobility of the Di people, endowed with the supreme power of the Sea God. The ocean is like his birth mother, while the land is his adoptive mother.
In the end, the four-person team sets out on a journey to find the four great River Gods and save terrestrial life…