What happens at the end? This question has exercised the minds of humans constantly through the ages. For Frosch, Xanthe, Iktar and Prethon (your author), the end of life was a transition to a post-dead state and they became Survivors, no longer part of the world but able to interact with it. They chose to be observers at first, but a chance encounter with an intruder into their refuge gave them the means to interact with the pre-dead.
Frosch came up with the idea of evicting a gang of squatters from a house in London and setting up a base with a library and cable TV. Frosch began to build a business empire with the assistance of his companions. The ladies, Xanthe and Iktar, also found new avenues for their talents. The Survivors met others of their kind, who were eager for diversion and who became willing partners in Frosch's plan to scam/hoax the whole world.
Survivors have abilities which are not available to the pre-dead, and were able to use them to simulate advanced technology, which governments with enough money could hire. Frosch's scam worked because the pre-dead wanted to believe in it. In fact, it worked so well that pre-dead criminals started to invent their own versions of the scam, which Frosch & Co. were able to enjoy exposing, as another source of diversion, while making themselves even richer.