三个家族共同经营着一座存放古代珍宝的水下宝库。在二十年前发生的一起神秘事件之后，幸存者易飒与搭档丁玉蝶、宗杭联手展开了一次新的探险，旨在揭开真相并寻回失落的宝物。
The Yellow River, the Yangtze River, and the Lancang River share a common source, and the three "Water Sprite" clans—Ding, Jiang, and Yi—have long dwelt along these waters. These "Water Sprites" possess the ability to move freely underwater and are skilled in *feng shui* geomancy, as well as the art of locating "dragon veins" and buried treasures. Yi Sa, the last of the Yi clan's Water Sprites, runs an "underwater banking" business along the Lancang River. During an operation to open an ancient underwater vault known as the "Golden Cauldron," she encounters and rescues Zong Hang, who is carrying the Jiang clan's ancestral token. Driven by a need to uncover the truth about the past and secure the "Water Essence Orb"—an artifact capable of saving her life—Yi Sa trains Zong Hang to become a professional Water Sprite. Together with Ding Yudie of the Ding clan, the trio descends into the "Ancestral Source Golden Cauldron." Meanwhile, Ding Changsheng, the patriarch of the Ding clan, also covets the Water Essence Orb as a means to command all three clans. A fierce confrontation is about to unfold at the bottom of Gongting Lake—a region known as the "Bermuda of Asia."
