Who is secret agent X-9 in Cat's Cradle and what is his significance?
In the novel Cat's Cradle by Kurt Vonnegut, "Secret Agent X-9" is a nickname that is given to the character of Frank Hoenniker, who is one of the sons of Felix Hoenniker: One of the forefathers of the atomic bomb.
The main character of the novel, John, is conducting an investigation for the purpose of writing a novel about the day when the atomic bomb was dropped in Hiroshima, and so he goes after another one of the sons of Hoenniker, Newt, to obtain more information.
However, the attention shifts to Frank because of his odd personality, which is what earns him the nickname of "Secret Agent X-9": He had a penchant for building things by himself, would make bugs battle each other out, maintained silence at all times, and was basically a loner.
Concisely, "Secret Agent X-9" is a nickname given to Frank Hoenniker, one of the sons of the co-creator of the atomic bomb Felix Hoenniker, and Frank earned such name for his odd and secretive behavior.