On a remote island, a suspected Nanyue site is discovered, and historian Gu Lin invites survival expert Wu Hen to help the archaeological team secure artifacts as a typhoon approaches. Unexpectedly, they uncover a cave far older than Lu Jia's era, leading them on an adventure to unravel an ancient mystery.

In the late Tang Dynasty, General Qian Liu and his troops encounter a fearsome two-headed beast while battling river pirates. As the creature escapes to the Qiantang River, it unleashes destruction, threatening the lives of all in its path.