Xie Bi'an and Fan Wujiu (the Black and White Guards) have always been like brothers. As they traveled to Nantai Bridge one day, they noticed it was going to rain. Xie told Fan to wait under the bridge while he returned home to get an umbrella. After Xie left, the rain began to pour and the river rose, but Fan, reluctant to break his promise, stayed under the bridge. Shortly after, Xie returned with the umbrella only to find that the bridge was now submerged and Fan nowhere to be seen...