I thought it was really interesting how DeLillo explicity connects Sister Edgar and J. Edgar Hoover as "Sister and Brother. A fantasy in cyberspace and a way of seeing the other side and a settling of differences that have less to do with gender than with difference itself, all argument, all conflict programmed out." Both characters exist in insular worlds without outside contact, yet cyberspace ultimately links them together albeit as only a "single fluctuating impulse now, a piece of coded information" (826). I'm not entirely sure as to what DeLillo means, but the ending seems very ambivalent, maybe intentionally so in order to mirror the increasing lack of a divide between what he calls cyberspace and the world.