"If you want to break Cao Gong, you should attack him with fire, and everything is ready except the east wind."
The best way to defeat Cao Cao is to attack with fire. Everything is ready now, except for the east wind.
From the forty-nine chapters of Romance of the Three Kingdoms, the original text is: Kongming took a pen and paper, and the screen retreated to the left and right. Sixteen words in the secret book say: "If you want to break Cao Gong, attack him with fire, and everything is ready, except the east wind." The original intention was that Zhou Yu planned to attack Cao Cao with fire and made all preparations. Suddenly, it occurred to him that he could not defeat the enemy without the east wind. Later, he used this metaphor to say that everything was ready, except the last important condition.