In order to frame Zhuge Liang, Zhou Yu asked Zhuge Liang to build 100 thousand arrows in ten days. Zhuge Liang decided to borrow twenty straw boats and sail for Cao Ying on a foggy day. Cao Cao suspected that there was an ambush in the fog and ordered them to shoot at random. When the fog cleared, Zhuge Liang hurriedly ordered the ship to be closed, and Cao Cao could not catch up. This enabled Zhuge Liang to borrow an arrow safely and foiled Zhou Yu's plot. It shows Zhuge Liang's efforts.