Chapter 4 finds Oedipa first at a stockholders' meeting of Yoyodyne, after which she finds a young man seemingly hip to the W.A.S.T.E. system. In a code-heavy conversation, he mentions the last of the true inventors, John Nefastis, who created a real, live Maxwell's Demon that will work with the aid of a psychic sensitive. Later, she finds an edition of The Courier's Tragedy with notably differing text, uncover a bit more about the Tristero's possible involvement in early American postal services, and talk to eminent philatelist Genghis Cohen.