In the 25th year of the Republic era, turmoil erupts along the Pujiang River.
Xuan Yi, a thousand-year-old black-scaled giant serpent from Changbai Mountain, seeks to monopolize the only chance to ascend into a dragon. Manipulating the river’s spiritual veins in secret, he stirs up violent storms and towering waves. Disguised as a Taoist priest, he deceives the people and incites them to seal off the Pujiang waterways, causing countless civilian casualties and trapping numerous flood dragons to their deaths.
In response, Bureau 749 urgently dispatches its elite team: Captain Lu Cheng, the immortal sorcerer Gu Yan, and the elegant qipao-clad beauty Jiang Tian. Arriving in Pujiang, the trio uncovers Xuan Yi’s sinister plot and joins forces in a fierce battle against the serpent’s true form. While suppressing the monster and reopening the waterways, they fight to protect the innocent. In the end, they resolve the crisis along the Pujiang River and restore peace to the region.
