Sentences in the chapter directly shows how important the codebreaking is. It is said that “it was a grim time, Midway or no Midway.” What’s more, John Redman said that “the work the women are now doing is too important to the war effort to risk a period of absence and disorganization.” (Liza Mundy, Code Girls) These two sentences show that without knowing the plain text there is no way to know the enemies’ strategies and women as code breakers are important forces in the war. If there are not many code breakers work days by days, the battle will be harder for the allies because of no advantages. At that time, Germany’s Lightning War and Japanese’s navy are strong. With the information of knowing where the enemies are going to attack or the position of the warships, the allies can attack with surprise to gain advantages. However, this needed the plaintext as a prerequisite. For America, the Naval Communications Annex works as an important part of the breaking code. In 1943, on February, there are about 4000 women breaking the code, which is a large amount of numbers. What’s more, they are able to keep secrets in their daily life. When others test them in daily life, the women do not easily tell about the secrets about their organizations. The ability of keeping secrets from enemies work as the basis of winning the war.