During the transition from the Wu Dynasty to the Jin Dynasty, Lei Huan of Yuzhang and Zhang Hua, a high-ranking official, unearthed two precious swords, Longquan (Dragon Spring) and Taia, in Fengcheng. They each kept one sword.

Later, when Lei Huan was wearing his sword and crossing Yanping Ford, he accidentally dropped it into the river.

Sometime after, Zhang Hua, also carrying his sword, arrived at the same ferry crossing. Suddenly, a dragon emerged from the water. The sword in Zhang Hua's hand also transformed into a dragon, and the two dragons soared into the sky and vanished.