The protagonist of these stories was involved in the creation of a global computer network designed to give ultimate economic control by keeping track of all human activity. Just before the system went live, the hero expressed his concerns about the possible misuse of such power to his superior, who gave the hero the chance to destroy his personal data before it was to be entered into the system. In taking this step the hero becomes non-existent as far as the system is concerned. Using backdoors in the central network, the hero is able to create identities for himself as needed. With this freedom he sets himself up as a freelance investigator and problem solver.
The following stories are included in the anthology:
"The Eve of RUMOKO": Project RUMOKO is a plan to use nuclear explosives to create artificial islands; the hero must identify and stop a saboteur on the project.
"'Kjwalll'kje'k'koothai'lll'kje'k": At a research station in the Bahamas a diver has died, apparently in an attack by a dolphin... But dolphins do not attack humans, and someone suspects foul play.
"Home Is the Hangman": A sentient space-exploration robot, lost years before, has apparently returned to Earth. One of its original designers has died under suspicious circumstances. Has the Hangman returned to kill its creators? The hero must find the Hangman and stop it, and time is running out. Although based on the same character as the other stories in this collection the theme is more closely related to the ideas Zelazny was developing in the short story "The Force That Through the Circuit Drives the Current" from the collection Unicorn Variations. This story won the 1976 Hugo Award for Best Novella.